Articles

Articles (peer-reviewed)

Sims, S., Woollacott, B., Inglis, M., Lortie-Forgues, H., & Foster, C. (2026). How should we communicate research findings to teachers? No difference in teachers’ intentions to use evidence across 512 versions of a research summary. Educational Researcher. Advance online publication. https://doi.org/10.3102/0013189X261494093

Mahak, S., Morsanyi, K., Foster, C., & Bin Sarfraz, W. (2026). Mathematics skills in autism: A systematic review and meta-analysis. Research in Autism, 139, Article 203052. https://doi.org/10.1016/j.reia.2026.203052

Foster, C., Hodgen, J., Küchemann, D., & Martin, D. (2026). Teaching low-attaining secondary school mathematics students: What practices do their teachers report? Canadian Journal of Science, Mathematics, and Technology Education. Advance online publication. https://doi.org/10.1007/s42330-026-00500-6

Foster, C. (2026). Editorial: Classroom Notes. International Journal of Mathematical Education in Science and Technology, 57(1), 1–2. https://doi.org/10.1080/0020739X.2025.2603079

Inglis, M., Foster, C., Lortie-Forgues, H., Simms, V., & Stokoe, E. (2025). Psychology and research assessment in the United Kingdom. Cogent Psychology, 12(1), Article 2570100. https://doi.org/10.1080/23311908.2025.2570100

Stannard, A., & Foster, C. (2025). Secondary school mathematics teachers’ accuracy at predicting student errors. School Science and Mathematics. Advance online publication. https://doi.org/10.1111/ssm.18404

Rainsford, E., & Foster, C. (2025). Confidence assessment, calibration, and gender. International Journal of Science and Mathematics Education, 23(8), 4073–4098. https://doi.org/10.1007/s10763-025-10615-1

Strauss, J., Foster, C., & Jay, T. (2025). The effectiveness of a Cover-Copy-Compare app for developing secondary school students’ mathematical procedural fluency with straight-line graphs. Canadian Journal of Science, Mathematics, and Technology Education, 25(2), 475–496. https://doi.org/10.1007/s42330-025-00381-1

Proshkin, V., & Foster, C. (2025). Challenges faced by Ukrainian students learning mathematics in UK schools. Cambridge Journal of Education, 55(1), 39–71. https://doi.org/10.1080/0305764X.2024.2444453

Foster, C. (2025). Feedback. Mathematical Gazette, 109(575), 353. https://doi.org/10.1017/mag.2025.10098

Foster, C. (2025). Editorial: Submission of articles. International Journal of Mathematical Education in Science and Technology, 56(1), 1–3. https://doi.org/10.1080/0020739X.2025.2452034

Inglis, M., Foster, C., Lortie-Forgues, H., & Stokoe, E. (2024). British education research and its quality: An analysis of Research Excellence Framework submissions. British Educational Research Journal, 50(5), 2495–2518. https://doi.org/10.1002/berj.4040

Foster, C., & Trundley, R. (2024). Adapting lesson study for early years practitioners. International Journal for Lesson and Learning Studies, 13(3), 225–231. https://doi.org/10.1108/IJLLS-07-2024-184

Foster, C., & Renie, P. (2024). Changes in students’ confidence calibration across a sequence of low-stakes confidence assessments. Asian Journal for Mathematics Education, 3(4), 406–427. https://doi.org/10.1177/27527263241298968

Kinnear, G., Hood, G., Lardet, E., Sheard, C., & Foster, C. (2024). Lecturers’ use of questions in undergraduate mathematics lectures. Journal of Mathematical Behavior, 76, Article 101190. https://doi.org/10.1016/j.jmathb.2024.101190

Foster, C., Woollacott, B., Francome, T., Shore, C., Peters, C., & Morley, H. (2024). Challenges in applying principles from cognitive science to the design of a school mathematics curriculum. The Curriculum Journal, 35(1), 489–513. https://doi.org/10.1002/curj.249

Foster, C., Francome, T., Shore, C., Hewitt, D., & Sangwin, C. (2024). Priority of operations: Necessary or arbitrary? For the Learning of Mathematics, 44(2), 24–26. https://www.foster77.co.uk/Foster%20et%20al.,%20FLM,%20Priority%20of%20operations%20-%20necessary%20or%20arbitrary.pdf

Foster, C. (2024). Methodological pragmatism in educational research: From qualitative-quantitative to exploratory-confirmatory distinctions. International Journal of Research and Method in Education, 47(1), 4–19. https://doi.org/10.1080/1743727X.2023.2210063

Kinnear, G., Jones, I., Sangwin, C., Alarfaj, M., Davies, B., Fearn, S., Foster, C., Heck, A., Henderson, K., Hunt, T., Iannone, P., Kontorovich, I., Larson, N., Lowe, T., Meyer, J. C., O’Shea, A., Rowlett, P., Sikurajapathi, I., & Wong, T. (2024). A collaboratively-derived research agenda for e-assessment in undergraduate mathematics. International Journal of Research in Undergraduate Mathematics Education, 10(2), 201–231. https://doi.org/10.1007/s40753-022-00189-6

Foster, C. (2024). \(\int_{0}^{2\pi} \sin^2 \theta \, d\theta\) from a shear-like transformation of a circle. Mathematical Gazette, 108(573), 541–542. https://doi.org/10.1017/mag.2024.132

Calleja, J., Foster, C., & Hodgen, J. (2024). Teachers’ structuring of mathematical inquiry lessons: Shifting from ‘task-first’ to ‘scaffolded inquiry’. Research in Mathematics Education, 26(3), 460–493. https://doi.org/10.1080/14794802.2023.2176915

Foster, C. (2024). Editorial: The peer review process. International Journal of Mathematical Education in Science and Technology, 55(1), 1–3. https://doi.org/10.1080/0020739X.2023.2293601

Foster, C. (2023). Problem solving in the mathematics curriculum: From domain-general strategies to domain-specific tactics. The Curriculum Journal, 34(4), 594–612. https://doi.org/10.1002/curj.213

Foster, C. (2023). A quotient effect size for educational interventions. International Journal of Research and Method in Education, 46(5), 528–537. https://doi.org/10.1080/1743727X.2023.2182877

Hodgen, J., Foster, C., Brown, M., & Martin, D. (2023). Low-attaining secondary school mathematics students’ perspectives on recommended teaching strategies. International Journal of Science and Mathematics Education, 22(6), 1325–1343. https://doi.org/10.1007/s10763-023-10420-8

Foster, C. (2023). Less is more: Improving by removing. Mathematical Gazette, 107(570), 386–398. https://doi.org/10.1017/mag.2023.90

Baldry, F., Mann, J., Horsman, R., Koiwa, D., & Foster, C. (2023). The use of carefully-planned board-work to support the productive discussion of multiple student responses in a Japanese problem-solving lesson. Journal of Mathematics Teacher Education, 26(2), 129–153. https://doi.org/10.1007/s10857-021-09511-6

Foster, C. (2023). Editorial. International Journal of Mathematical Education in Science and Technology, 54(1), 1–3. https://doi.org/10.1080/0020739X.2023.2153962

Foster, C. (2022). Using coherent representations of number in the school mathematics curriculum. For the Learning of Mathematics, 42(3), 21–27. https://www.foster77.co.uk/Foster,%20Using%20coherent%20representations%20of%20number%20in%20the%20school%20mathematics%20curriculum.pdf

Foster, C., Woodhead, S., Barton, C., & Clark-Wilson, A. (2022). School students’ confidence when answering diagnostic questions online. Educational Studies in Mathematics, 109(3), 491–521. https://doi.org/10.1007/s10649-021-10084-7

Foster, C. (2022). Implementing confidence assessment in low-stakes, formative mathematics assessments. International Journal of Science and Mathematics Education, 20(7), 1411–1429. https://doi.org/10.1007/s10763-021-10207-9

Foster, C., Barichello, L., Bustang, B., Najjuma, R., & Saralar-Aras, İ. (2022). Decolonizing educational design for school mathematics. For the Learning of Mathematics, 42(2), 9–14. https://www.foster77.co.uk/Foster%20et%20al.%20Decolonizing%20educational%20design%20for%20school%20mathematics.pdf

Foster, C., Burkhardt, H., & Schoenfeld, A. (2022). Crisis-ready educational design: The case of mathematics. The Curriculum Journal, 33(4), 519–535. https://doi.org/10.1002/curj.159

Jones, I., Foster, C., & Hunter, J. (2022). Comparing examination standards without graded candidate scripts. European Journal of Mathematics and Science Education, 3(2), 79–90. https://doi.org/10.12973/ejmse.3.2.79

Hodgen, J., Foster, C., & Brown, M. (2022). Low attainment in mathematics: An analysis of 60 years of policy discourse in England. The Curriculum Journal, 33(1), 5–24. https://doi.org/10.1002/curj.128

Foster, C. (2022). Editorial. International Journal of Mathematical Education in Science and Technology, 53(1), 1–3. https://doi.org/10.1080/0020739X.2022.2030990

Foster, C., Francome, T., Hewitt, D., & Shore, C. (2021). Principles for the design of a fully-resourced, coherent, research-informed school mathematics curriculum. Journal of Curriculum Studies, 53(5), 621–641. https://doi.org/10.1080/00220272.2021.1902569

Calleja, J., Foster, C., & Hodgen, J. (2021). Integrating ‘just-in-time’ learning in the design of mathematics professional development. Mathematics Teacher Education and Development, 23(2), 79–101. https://mted.merga.net.au/index.php/mted/article/view/599

Foster, C. (2021). Editorial. International Journal of Mathematical Education in Science and Technology, 52(1), 1–2. https://doi.org/10.1080/0020739X.2021.1861701

Marks, R., Foster, C., Barclay, N., Barnes, A., & Treacy, P. (2021). A comparative synthesis of UK mathematics education research: What are we talking about and do we align with international discourse? Research in Mathematics Education, 23(1), 39–62. https://doi.org/10.1080/14794802.2020.1725612

Seino, T., & Foster, C. (2020). Analysis of the final comments provided by a knowledgeable other in Lesson Study. Journal of Mathematics Teacher Education, 24(5), 507–528. https://doi.org/10.1007/s10857-020-09468-y

Foster, C. (2020). Editorial. International Journal of Mathematical Education in Science and Technology, 51(1), 1–2. https://doi.org/10.1080/0020739X.2020.1700609

Foster, C., & Inglis, M. (2019). Mathematics teacher professional journals: What topics appear and how has this changed over time? International Journal of Science and Mathematics Education, 17(8), 1627–1648. https://doi.org/10.1007/s10649-018-9937-4

Foster, C. (2019). Editorial. International Journal of Mathematical Education in Science and Technology, 50(1), 1–2. https://doi.org/10.1080/0020739X.2019.1573786

Inglis, M., & Foster, C. (2018). Five decades of mathematics education research. Journal for Research in Mathematics Education, 49(4), 462–500. https://doi.org/10.5951/jresematheduc.49.4.0462

Foster, C. (2018). Developing mathematical fluency: Comparing exercises and rich tasks. Educational Studies in Mathematics, 97(2), 121–141. https://doi.org/10.1007/s10649-017-9788-x

Foster, C., & Inglis, M. (2017). Teachers’ appraisals of adjectives relating to mathematics tasks. Educational Studies in Mathematics, 95(3), 283–301. https://doi.org/10.1007/s10649-017-9750-y

Foster, C. (2016). Confidence and competence with mathematical procedures. Educational Studies in Mathematics, 91(2), 271–288. https://doi.org/10.1007/s10649-015-9660-9

Wake, G., Swan, M., & Foster, C. (2016). Professional learning through the collaborative design of problem-solving lessons. Journal of Mathematics Teacher Education, 19(2), 243–260. https://doi.org/10.1007/s10857-015-9332-9

Foster, C., & De Villiers, M. (2016). The definition of the scalar product: An analysis and critique of a classroom episode. International Journal of Mathematical Education in Science and Technology, 47(5), 750–761. https://doi.org/10.1080/0020739X.2015.1117148

Foster, C. (2016). Proof without words: Integer right triangle hypotenuses without Pythagoras. The College Mathematics Journal, 47(2), 101. https://doi.org/10.4169/college.math.j.47.2.101 pdf

Foster, C., & Martin, D. (2016). Two-dice horse race. Teaching Statistics, 38(3), 98–101. https://doi.org/10.1111/test.12108 pdf (Spreadsheet resource xlsm)

Foster, C. (2015). Closed but provocative questions: Curves enclosing unit area. International Journal of Mathematical Education in Science and Technology, 46(5), 776–783. https://doi.org/10.1080/0020739X.2014.992989 pdf

Foster, C. (2015). Exploiting unexpected situations in the mathematics classroom. International Journal of Science and Mathematics Education, 13(5), 1065–1088. https://doi.org/10.1007/s10763-014-9515-3

Foster, C. (2015). The convergent–divergent model: An opportunity for teacher–learner development through principled task design. Educational Designer, 2(8), Article 28. https://www.educationaldesigner.org/ed/volume2/issue8/article28/index.htm

Foster, C. (2015). Expression polygons. Mathematics Teacher, 109(1), 62–65. https://doi.org/10.5951/mathteacher.109.1.0062 pdf (Resource sheet doc)

Foster, C. (2014). Minimal interventions in the teaching of mathematics. European Journal of Science and Mathematics Education, 2(3), 147–154. https://doi.org/10.30935/scimath/9407

Foster, C. (2014). Confidence trick: The interpretation of confidence intervals. Canadian Journal of Science, Mathematics, and Technology Education, 14(1), 23–34. https://doi.org/10.1080/14926156.2014.874615

Foster, C. (2014). Equal volumes of revolution. Mathematical Gazette, 98(543), 504–507. https://doi.org/10.1017/S0025557200008287 pdf

Foster, C. (2014). Getting goose bumps about teaching evolution. Primary Science, 131, 5–7. https://www.foster77.co.uk/Foster,%20Primary%20Science,%20Getting%20goose%20bumps%20about%20teaching%20evolution.pdf

Foster, C. (2013). Resisting reductionism in mathematics pedagogy. The Curriculum Journal, 24(4), 563–585. https://doi.org/10.1080/09585176.2013.828630

Foster, C. (2013). Mathematical études: Embedding opportunities for developing procedural fluency within rich mathematical contexts. International Journal of Mathematical Education in Science and Technology, 44(5), 765–774. https://doi.org/10.1080/0020739X.2013.770089

Foster, C. (2013). Problems with generalising: Pythagoras in n dimensions. Australian Senior Mathematics Journal, 27(1), 8–11. https://www.foster77.co.uk/Foster,%20Australian%20Senior%20Mathematics%20Journal,%20Problems%20with%20generalising.pdf

Foster, C. (2012). Creationism as a misconception: Socio-cognitive conflict in the teaching of evolution. International Journal of Science Education, 34(14), 2171–2180. https://doi.org/10.1080/09500693.2012.692102

Foster, C. (2012). How to manipulate test scores. The College Mathematics Journal, 43(2), 121–122. https://doi.org/10.4169/college.math.j.43.2.121 pdf

Foster, C. (2012). Working without a safety net. The Australian Mathematics Teacher, 68(2), 25–29. https://www.foster77.co.uk/Foster,%20Australian%20Mathematics%20Teacher,%20Working%20Without%20a%20Safety%20Net.pdf

Foster, C. (2012). The probability distribution for a biased spinner. Teaching Statistics, 34(1), 41–43. https://doi.org/10.1111/j.1467-9639.2011.00481.x pdf

Foster, C. (2012). Quadratic doublets. Mathematical Gazette, 96(536), 264–266. https://doi.org/10.1017/S0025557200004514 pdf

Foster, C. (2012). Squares within squares. Mathematical Gazette, 96(536), 328–331. https://doi.org/10.1017/S002555720000468X pdf

Foster, C. (2012). Symmetrical cubics. Mathematical Gazette, 96(536), 109–112. https://doi.org/10.1017/S0025557200004071 pdf

Foster, C. (2012). Orthogonal mappings. Mathematical Gazette, 96(536), 112–115. https://doi.org/10.1017/S0025557200004083 pdf

Foster, C. (2012). Taking a short cut through Pascal’s triangle. Mathematical Gazette, 96(536), 142–145. https://doi.org/10.1017/S0025557200004198 pdf

Foster, C. (2012). When is a parabola not a parabola? Mathematics Teacher, 105(7), 486–487. https://www.foster77.co.uk/Foster,%20Mathematics%20Teacher,%20When%20is%20a%20Parabola%20Not%20a%20Parabola.pdf

Foster, C. (2011). Student-generated questions in mathematics teaching. Mathematics Teacher, 105(1), 26–31. https://doi.org/10.5951/mathteacher.105.1.0026 pdf

Foster, C. (2011). A slippery slope: Resolving cognitive conflict in mechanics. Teaching Mathematics and its Applications, 30(4), 216–221. https://doi.org/10.1093/teamat/hrr015

Foster, C. (2011). Peripheral mathematical knowledge. For the Learning of Mathematics, 31(3), 24–26. https://www.foster77.co.uk/Foster,%20For%20The%20Learning%20of%20Mathematics,%20Peripheral%20Mathematical%20Knowledge.pdf

Foster, C. (2011). Productive ambiguity in the learning of mathematics. For the Learning of Mathematics, 31(2), 3–7. https://www.foster77.co.uk/Foster,%20For%20The%20Learning%20of%20Mathematics,%20Productive%20Ambiguity%20in%20the%20Learning%20of%20Mathematics.pdf

Foster, C. (2011). The significance of a square-root rule. The American Statistician, 65(4), 222. https://doi.org/10.1198/tas.2011.11160 pdf

Foster, C. (2011). A comment on Schnell and Mendoza. Mathematical Gazette, 95(533), 357. https://doi.org/10.1017/S0025557200003284 pdf

Foster, C. (2010). A fortuitous value. Mathematical Gazette, 94(530), 335. https://doi.org/10.1017/S0025557200006719 pdf

Foster, C. (2009). Isometric graphs. Mathematical Gazette, 93(527), 289–292. https://doi.org/10.1017/S0025557200184840 pdf

Foster, C. (2009). Knowing your limitations. Teaching Statistics, 31(2), 59–60. https://doi.org/10.1111/j.1467-9639.2009.00349.x pdf

Foster, C. (2008). Avoiding Pythagoras. Mathematical Gazette, 92(523), 110–111. https://doi.org/10.1017/S0025557200182683 pdf

Book chapters

Foster, C. (2027). Section 1: The curriculum: Commentary. In A. Coles, V. Hatisaru, J. Ingram, E. Nardi, H. Povey, & T. Rowland (Eds.), Research in Mathematics Education in the UK: Findings from the first forty years of the British Society for Research into Learning Mathematics (pp. XX–XX). Springer.

Foster, C. (2025). Foreword. In X. K. Yan, A. Mamolo, & I. Kontorovich (Eds.), Where is the Mathematics in Your Math Education Research? Personal accounts of leading educators (pp. v–vii). Springer. https://link.springer.com/content/pdf/bfm:978-3-031-83907-8/1

Hodgen, J., & Foster, C. (2024). What’s so hard about algebra? In J. Berry & C. Pritchard (Eds.), Learning mathematics: What the experts say (pp. 159–161). Mathematical Association. https://www.foster77.co.uk/Hodgen%20&%20Foster,%20What's%20so%20hard%20about%20algebra.pdf

Foster, C. (2021). Checking for understanding. In E. Southall (Ed.), If I only tell you one thing (pp. 3–9). Mathematical Association. https://www.foster77.co.uk/Foster,%20Checking%20for%20understanding.pdf

Baldry, F., & Foster, C. (2019). Lesson study partnerships in initial teacher education. In P. Wood, D. Larssen, W. Cajkler, & N. Helgevold (Eds.), Lesson Study in Initial Teacher Education: A critical perspective (pp. 147–160). Emerald Publishing. https://doi.org/10.1108/978-1-78756-797-920191011 pdf

Baldry, F., & Foster, C. (2019). Lesson study in mathematics Initial Teacher Education in England. In R. Huang, A. Takahashi, & P. da Ponte (Eds.), Theory and Practice of Lesson Study in Mathematics: An international perspective (pp. 577–594). Springer. https://doi.org/10.1007/978-3-030-04031-4_28 pdf

Swan, M., & Foster, C. (2018). Formative assessment lessons. In D. R. Thompson, M. Burton, A. Cusi, & D. Wright (Eds.), Classroom assessment in mathematics: Perspectives from around the globe (pp. 11–24). Springer. https://doi.org/10.1007/978-3-319-73748-5_2 pdf

Foster, C. (2018). A picture is worth a thousand exercises. In A. Watson (Ed.), Variation in Mathematics Teaching and Learning: A collection of writing from ATM: Mathematics Teaching (pp. 29–30). Association of Teachers of Mathematics. https://www.atm.org.uk/Shop/Variation-in-mathematics-A-collection-of-writings-from-ATM-Mathematics-Teaching/REA027

Book reviews (peer-reviewed)

Foster, C. (2017). [Review of the book Validity in educational and psychological assessment, by P. E. Newton & S. D. Shaw]. Research in Mathematics Education, 19(2), 108–111. https://doi.org/10.1080/14794802.2017.1318086

Foster, C. (2014). [Review of the book How to study for a mathematics degree, by L. Alcock]. Mathematical Gazette, 98(542), 377–378. https://doi.org/10.1017/S0025557200001625 pdf

Foster, C. (2013). [Review of the book Teaching with tasks for effective mathematics learning, by P. Sullivan, D. Clarke, & B. Clarke]. Research in Mathematics Education, 15(3), 309–313. https://doi.org/10.1080/14794802.2013.830357 pdf

Conference proceedings (peer-reviewed)

O’Brien, D., Riding, K., Rumbelow, M., Moeller, K., & Foster, C. (2026). Sense-making in extended reality: Exploring embodied mathematical interactions using smart devices and head-mounted displays. In H. Krzywacki, M. Hähkiöniemi, E. Haataja, M. S. Hannula, & P. Hästö (Eds.), Proceedings of the 49th Conference of the International Group for the Psychology of Mathematics Education: General Contributions (pp. 328–329). PME. https://www.helsinki.fi/assets/drupal/2026-07/PME49_July_WG%20and%20SE%20PME%2049.pdf

O’Brien, D., Moeller, K., & Foster, C. (2026). Integrating fraction representations using a novel augmented reality spiral design. In H. Krzywacki, M. Hähkiöniemi, E. Haataja, M. S. Hannula, & P. Hästö (Eds.), Proceedings of the 49th Conference of the International Group for the Psychology of Mathematics Education: Research Reports (p. 755). PME. https://www.helsinki.fi/assets/drupal/2026-07/PME49_FINAL_PP%20PME%2049.pdf

O’Brien, D., Moeller, K., & Foster, C. (2025). A conceptual framework for optimising number line development in augmented reality [Abstract]. In T. Fujita (Ed.), BSRLM Day Conference Proceedings. Research in Mathematics Education, 27(2), 363–366. https://doi.org/10.1080/14794802.2025.2505575

O’Brien, D., Moeller, K., & Foster, C. (2025). A conceptual framework for optimising number line development in augmented reality. In T. Fujita (Ed.), Proceedings of the British Society for Research into Learning Mathematics, 45(1). https://bsrlm.org.uk/wp-content/uploads/2025/05/BSRLM-CP-45-1-8.pdf

O’Brien, D., Moeller, K., & Foster, C. (2025). A framework for design decisions for developing an augmented reality number line resource. In Proceedings of the 48th Conference of the International Group for the Psychology of Mathematics Education (PME 48) (p. 299). PME. https://www.igpme.org/wp-content/uploads/2025/07/PME48_GeneralContributions_ISSN_3081-0833.pdf

Flint, T., Stokoe, E., Seabridge, K., Jay, T., Dowker, A., Foster, C., Scerif, G., & Simms, V. (2024). Two interactional practices used by early years practitioners to encourage children to “try again” in preschool mathematics learning. In M. N. Ríordáin & K. Erath (Eds.), Proceedings of the Sixteenth ERME Topic Conference on Language and Social Interaction in Heterogeneous Mathematics Classrooms (pp. 36–43). ERME. https://hal.science/hal-04833321v1

Barmby, P., Foster, C., Jones, I., Kelly, J., & Milinkovic, J. (2023). Using a comparative judgement approach to assess the problem-solving skills of primary school pupils. In Proceedings of the 46th Conference of the International Group for the Psychology of Mathematics Education (IGPME) (Vol. 1, p. 229). PME. https://irf.fhnw.ch/server/api/core/bitstreams/ca1f87dc-172a-4b3f-a2a6-21ea89d56644/content#page=277

Barmby, P., Jones, I., Foster, C., & Milinkovic, J. (2021). Using a comparative judgement approach to assess the problem-solving skills of primary school pupils. In Proceedings of the 29th Conference of the Southern African Association for Research in Mathematics, Science and Technology Education (SAARMSTE) (pp. 9–13). SAARMSTE. https://repository.lboro.ac.uk/articles/conference_contribution/Using_a_comparative_judgement_approach_to_assess_the_problem-solving_skills_of_primary_school_pupils/12933287/1

Wake, G., Foster, C., & Nishimura, K. (2020). Lesson study: A case of expansive learning. In Proceedings of the 25th International Commission on Mathematical Instruction. ICMI. https://www.foster77.co.uk/Wake,%20Foster,%20&%20Nishimura%20Lesson%20study%20A%20case%20of%20expansive%20learning.pdf

Swan, M., & Foster, C. (2016). Formative assessment lessons for concept development and problem solving. In Proceedings of the 13th International Congress on Mathematical Education. ICME. https://www.foster77.co.uk/Swan%20&%20Foster,%20Formative%20Assessment%20Lessons.pdf

Kent, G., & Foster, C. (2016). Re-conceptualising conceptual understanding in mathematics. In K. Krainer & N. Vondrová (Eds.), Proceedings of the Ninth Congress of European Research in Mathematics Education (CERME9) (pp. 2656–2661). CERME. https://hal.science/hal-01289445/document

Wake, G., Foster, C., & Swan, M. (2016). Understanding issues in teaching mathematical modelling: Lessons from lesson study. In K. Krainer & N. Vondrová (Eds.), Proceedings of the Ninth Congress of European Research in Mathematics Education (CERME9) (pp. 937–943). CERME. https://hal.science/hal-01287270/document

Foster, C., Wake, G., & Swan, M. (2014). Mathematical knowledge for teaching problem solving: Lessons from lesson study. In S. Oesterle, C. Nicol, P. Liljedahl, & D. Allan (Eds.), Proceedings of the Joint Meeting of PME 38 and PME-NA 36 (Vol. 3, pp. 97–104). PME. https://www.foster77.co.uk/Foster,%20Wake%20&%20Swan,%20PME%202014,%20Mathematical%20knowledge%20for%20teaching%20problem%20solving%20-%20Lessons%20from%20lesson%20study.pdf

Wake, G., Foster, C., & Swan, M. (2014). Understanding issues in mathematical problem solving and modelling: Lessons from lesson study. In S. Oesterle, C. Nicol, P. Liljedahl, & D. Allan (Eds.), Proceedings of the Joint Meeting of PME 38 and PME-NA 36 (Vol. 6, p. 259). PME. https://www.foster77.co.uk/Wake,%20Foster%20&%20Swan,%20Understanding%20issues%20in%20mathematical%20problem%20solving%20and%20modelling.pdf

Foster, C. (2014). “Can’t you just tell us the rule?” Teaching procedures relationally. In S. Pope (Ed.), Proceedings of the 8th British Congress of Mathematics Education (Vol. 34, No. 2, pp. 151–158). University of Nottingham. https://www.bsrlm.org.uk/wp-content/uploads/2016/09/BCME8-20.pdf

Wake, G., Foster, C., & Swan, M. (2014). Teacher knowledge for modelling and problem solving. In S. Pope (Ed.), Proceedings of the 8th British Congress of Mathematics Education (Vol. 34, No. 2, pp. 335–342). University of Nottingham. https://www.bsrlm.org.uk/wp-content/uploads/2016/09/BCME8-43.pdf

Wake, G., Foster, C., & Swan, M. (2013). A theoretical lens on lesson study: Professional learning across boundaries. In A. M. Lindmeier & A. Heinze (Eds.), Proceedings of the 37th Conference of the International Group for the Psychology of Mathematics Education (Vol. 4, pp. 369–376). PME. https://www.foster77.co.uk/Wake,%20Foster%20&%20Swan%20A%20theoretical%20lens%20on%20lesson%20study.pdf

Reports

Marks, R., Barclay, N., Barnes, A., Allen, B., Foster, C., & Hodgen, J. (2023). The prevalence and use of textbooks and curriculum resources in primary mathematics. Nuffield Foundation. https://cris.brighton.ac.uk/ws/portalfiles/portal/40340288/The_Prevalence_and_Use_of_Textbooks_and_Curriculum_Resources_Final_Report_120623.pdf

Foster, C. (2022). Learning times tables through systematic connections. https://www.foster77.co.uk/Learning%20Times%20Tables%20Through%20Systematic%20Connections.pdf

Foster, C. (2022, August). Mathematics curriculum resourcing in England: What might the future hold? Research on Global Trends in Mathematics and Mathematics Textbooks: Bulletin of the Textbook Research Center, 198–202. https://textbook-rc.or.jp/wp-content/uploads/2022/10/80160bf7b38e4d1fd6ab6aa113f8bd3e.pdf (English version)

Wake, G., Foster, C., & Hatakenaka, S. (2020). Developing a sustainable and scalable model for the professional learning of mathematics teachers: Final report of the LeMaPS (Lessons for Mathematical Problem Solving) project. University of Nottingham. https://www.nottingham.ac.uk/research/groups/crme/documents/lemaps-report.pdf

Hodgen, J., Barclay, N., Foster, C., Gilmore, C., Marks, R., & Simms, V. (2020). Early years and Key Stage 1 mathematics teaching: Evidence review. Education Endowment Foundation. https://educationendowmentfoundation.org.uk/education-evidence/evidence-reviews/early-years-and-key-stage-1-mathematics-teaching

Education Endowment Foundation. (2020). Improving mathematics in the early years and Key Stage 1: Guidance report. https://educationendowmentfoundation.org.uk/education-evidence/guidance-reports/early-maths

Hodgen, J., Coe, R., Foster, C., Brown, M., Higgins, S., & Küchemann, D. (2020). Low attainment in mathematics: An investigation focusing on Year 9 students in England. University College London Institute of Education. https://discovery.ucl.ac.uk/id/eprint/10091720/

Hodgen, J., Coe, R., Foster, C., Brown, M., Higgins, S., & Küchemann, D. (2020). Low attainment in mathematics: An investigation focusing on Year 9 students in England: Technical report. University College London Institute of Education. https://discovery.ucl.ac.uk/id/eprint/10099162/

Education Endowment Foundation. (2017). Improving mathematics in Key Stages Two and Three: Guidance report. https://educationendowmentfoundation.org.uk/education-evidence/guidance-reports/maths-ks-2-3

Hodgen, J., Foster, C., Marks, R., & Brown, M. (2018). Evidence for review of mathematics teaching: Improving mathematics in Key Stages Two and Three. Education Endowment Foundation. https://educationendowmentfoundation.org.uk/education-evidence/evidence-reviews/mathematics-in-key-stages-2-and-3

Media and engagement

Foster, C. (2026, October 5). Two-minute math: Mathematical explanations using animations [Blog post]. https://blog.lboro.ac.uk/cmc/2026/10/05/two-minute-math-mathematical-explanations-using-animations/

Foster, C. (2026, June 22). Beyond the ‘to-do list’ curriculum: Why school mathematics needs to focus on big mathematical ideas [Blog post]. https://blog.lboro.ac.uk/cmc/2026/06/22/beyond-the-to-do-list-curriculum-why-school-mathematics-needs-to-focus-on-big-mathematical-ideas/

Stannard, A., & Foster, C. (2026, May 11). Predicting the unpredictable: Can mathematics teachers learn to anticipate student errors? [Blog post]. https://blog.lboro.ac.uk/cmc/2026/05/11/predicting-the-unpredictable-can-mathematics-teachers-learn-to-anticipate-student-errors/

Stokoe, E., Inglis, M., Foster, C., Lortie-Forgues, H., & Simms, V. (2025, November 7). Evaluating the evaluation of psychology in UK universities. The Psychologist. https://www.bps.org.uk/psychologist/evaluating-evaluation-psychology-uk-universities

Proshkin, V., & Foster, C. (2025, March 3). Navigating mathematics learning: Challenges for Ukrainian refugee students in UK schools [Blog post]. https://blog.lboro.ac.uk/cmc/2025/03/03/navigating-mathematics-learning-challenges-for-ukrainian-refugee-students-in-uk-schools/

Foster, C. (2025). Using cognitive science to design a school mathematics curriculum. U3A Mathematics and Statistics Newsletter, 2(27), 1–2. https://www.u3a.org.uk/edocman-downloads/mathematics-and-statistics-newsletter-december-2024/download

Foster, C. (2024, May 8). Using principles from cognitive science to design a school mathematics curriculum [Blog post]. BERA Blog. https://www.bera.ac.uk/blog/using-principles-from-cognitive-science-to-design-a-school-mathematics-curriculum

Foster, C. (2024, March 22). The launch of the LUMEN curriculum [Blog post]. https://blog.lboro.ac.uk/cmc/2024/03/22/the-launch-of-the-lumen-curriculum/

Foster, C. (2024, February 28). Understanding how the brain works can transform how school students learn maths. The Conversation. https://theconversation.com/understanding-how-the-brain-works-can-transform-how-school-students-learn-maths-223941

Foster, C., & Francome, T. (2023). Teaching Dilemma 1: If they probably won’t know, should I ask anyway? Loughborough University Mathematics Education Network. https://www.foster77.co.uk/Foster%20&%20Francome,%20Teaching%20Dilemma%201.pdf

Foster, C. (2023, June 29). The teaching of problem solving in the school mathematics curriculum [Blog post]. BERA Blog. https://www.bera.ac.uk/blog/the-teaching-of-problem-solving-in-the-school-mathematics-curriculum

Foster, C. (2023, June 13). Teaching mathematical problem solving in the school curriculum [Blog post]. https://blog.lboro.ac.uk/cmc/2023/06/13/teaching-mathematical-problem-solving-in-the-school-curriculum/

Gordon, B. (Host). (2021, December 2). Episode 4: Colin Foster – Problem solving in the mathematics curriculum [Audio podcast episode]. In BAGs to Learn Podcast. https://anchor.fm/ben-gordon83/episodes/Episode-4---Colin-Foster---Problem-Solving-in-the-mathematics-curriculum-e1b5ic3

Barton, C. (Host). (2021, June 21). Writing a maths curriculum with Colin Foster [Audio podcast episode]. In Mr Barton Maths Podcast. http://www.mrbartonmaths.com/blog/research-in-action-16-writing-a-maths-curriculum-with-colin-foster/

Foster, C., Francome, T., Hewitt, D., & Shore, C. (2021, May 18). Designing a fully-resourced, research-informed school mathematics curriculum [Blog post]. https://blog.lboro.ac.uk/cmc/2021/05/18/designing-a-fully-resourced-research-informed-school-mathematics-curriculum/

Foster, C. (2021, March 31). Developing fluency with procedures without using traditional exercises [Video]. YouTube. https://www.youtube.com/watch?v=OSrnbf9YyO0

Foster, C., & Burkhardt, H. (2020, September 2). UK Parliament: Education Committee: The impact of COVID-19 on education and children’s services: CIE0382 [Evidence submission]. HMSO. https://committees.parliament.uk/writtenevidence/9074/default/

AssocTeachersMaths. (2020, July 13). Armchair responses to classroom events - with Colin Foster [Video]. YouTube. https://youtu.be/L0ovhillL0c

Foster, C. (2019, October 8). Moving forward with formative assessment [Blog post]. https://www.lboro.ac.uk/services/lumen/blog/formative-assessment-blog-post/

Barton, C. (Host). (2018, July 17). Slice of advice: What did you learn this year? [Audio podcast episode]. In Mr Barton Maths Podcast. http://www.mrbartonmaths.com/blog/slice-of-advice-what-did-you-learn-this-year/

Foster, C. (2018, June 15). Creative approaches to practising mathematical procedures [Blog post]. http://maths4maryams.org/mathed/wp-content/uploads/2018/06/Wikiletters-4.pdf (English) or https://maths4maryams.org/mathed/wp-content/uploads/2018/08/Foster-WikiLetter.pdf (Farsi).

Foster, C. (2018, March 23). Interview by BBC Breakfast [Television broadcast]. BBC1, British Broadcasting Corporation.

Foster, C. (2018, March 23). Interview by Newsday [Radio broadcast]. BBC World Service, British Broadcasting Corporation.

Foster, C. (2018, March 23). Interview by Newsroom [Radio broadcast]. BBC World Service, British Broadcasting Corporation.

Barton, C. (Host). (2017, November 26). Colin Foster: Mathematical etudes, confidence and questioning [Audio podcast episode]. In Mr Barton Maths Podcast. http://www.mrbartonmaths.com/blog/colin-foster-mathematical-etudes-confidence-and-questioning/

Inglis, M., & Foster, C. (2017, June 9). How do teachers describe mathematics tasks? [Blog post]. https://bsrlm.org.uk/teachers-describe-mathematics-tasks/

Blog

Foster, C. (2023, March 30). Teaching specific tactics for problem solving [Blog post]. https://blog.foster77.co.uk/2023/03/teaching-specific-strategies-for.html

Foster, C. (2023, March 16). Crocodiles and inequality signs [Blog post]. https://blog.foster77.co.uk/2023/03/crocodiles-and-inequality-signs.html

Foster, C. (2023, March 2). Are probabilities and inequalities approximate? [Blog post]. https://blog.foster77.co.uk/2023/03/are-probabilities-and-inequalities.html

Foster, C. (2023, February 16). Don’t forget the units? [Blog post]. https://blog.foster77.co.uk/2023/02/dont-forget-units.html

Foster, C. (2023, February 2). Non-expository video clips [Blog post]. https://blog.foster77.co.uk/2023/02/non-expository-video-clips.html

Foster, C. (2023, January 19). Is zero really a number? [Blog post]. https://blog.foster77.co.uk/2023/01/is-zero-really-number.html

Foster, C. (2023, January 5). Proportionality [Blog post]. https://blog.foster77.co.uk/2023/01/proportionality.html

Foster, C. (2022, December 22). Mixing the dimensions in models of number [Blog post]. https://blog.foster77.co.uk/2022/12/mixing-dimensions-in-models-of-number.html

Foster, C. (2022, December 8). Dividing into thirds [Blog post]. https://blog.foster77.co.uk/2022/12/dividing-into-thirds.html

Foster, C. (2022, November 24). Fractions as factors [Blog post]. https://blog.foster77.co.uk/2022/10/fractions-as-factors.html

Foster, C. (2022, November 10). Is area more difficult than volume? [Blog post]. https://blog.foster77.co.uk/2022/11/is-area-more-difficult-than-volume.html

Foster, C. (2022, October 27). Butterfly effects when adapting tasks [Blog post]. https://blog.foster77.co.uk/2022/10/butterfly-effects-when-adapting-tasks.html

Foster, C. (2022, October 13). How open should a question be? [Blog post]. https://blog.foster77.co.uk/2022/10/how-open-should-question-be.html

Foster, C. (2022, September 29). Tasks that can’t fail [Blog post]. https://blog.foster77.co.uk/2022/09/tasks-that-cant-fail.html

Foster, C. (2022, September 15). Always simplify your answer [Blog post]. https://blog.foster77.co.uk/2022/09/always-simplify-your-answer.html

Foster, C. (2022, September 1). Interactive introductions [Blog post]. https://blog.foster77.co.uk/2022/09/interactive-introductions.html

Foster, C. (2022, August 18). The differentiator [Blog post]. https://blog.foster77.co.uk/2022/08/the-differentiator.html

Foster, C. (2022, August 4). Misremembering Goldbach’s conjecture [Blog post]. https://blog.foster77.co.uk/2022/08/misremembering-goldbachs-conjecture.html

Foster, C. (2022, July 21). Making rounding interesting [Blog post]. https://blog.foster77.co.uk/2022/07/making-rounding-interesting.html

Foster, C. (2022, July 7). A football on the roof [Blog post]. https://blog.foster77.co.uk/2022/07/a-football-on-roof.html

Foster, C. (2022, June 23). Lines of not-very-good fit [Blog post]. https://blog.foster77.co.uk/2022/06/lines-of-not-very-good-fit.html

Foster, C. (2022, June 9). Motivation for measurement [Blog post]. https://blog.foster77.co.uk/2022/06/motivation-for-measurement.html

Foster, C. (2022, May 26). Are two cars better than one? [Blog post]. https://blog.foster77.co.uk/2022/05/are-two-cars-better-than-one.html

Foster, C. (2022, May 12). Learning times tables efficiently [Blog post]. https://blog.foster77.co.uk/2022/05/learning-times-tables-efficiently.html

Foster, C. (2022, April 28). Tangible contexts for mathematics [Blog post]. https://blog.foster77.co.uk/2022/04/tangible-contexts-for-mathematics.html

Foster, C. (2022, April 14). Intro-ducing and outro-ducing methods [Blog post]. https://blog.foster77.co.uk/2022/04/intro-ducing-and-outro-ducing-methods.html

Professional articles

Foster, C. (2027). Isn’t it odd? Mathematics in School, 56(X), XX–XX.

Foster, C. (2027). Teaching fractions by zooming. Mathematics in School, 56(X), XX–XX.

Foster, C. (2027). Persevere, or just give up? Teach Secondary, 16(2), XX.

Foster, C. (2027). Compound shapes. Teach Secondary, 16(2), XX.

Foster, C. (2027). Questions pupils ask: Where are the ‘oneths’? Mathematics in School, 56(1), XX–XX.

Foster, C. (2027). But there’s no time! Teach Secondary, 16(1), XX.

Foster, C. (2027). Quadratic sequences. Teach Secondary, 16(1), XX.

Foster, C. (2026). Assumptions and proof by induction. Scottish Mathematical Council Journal, 56, XX–XX.

Foster, C. (2026). Why school mathematics doesn’t need gamifying. Mathematics Teaching, 302, 41–43.

Foster, C. (2026). Questions pupils ask: Why does a transformed graph move the wrong way? Mathematics in School, 55(5), 11–13. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20QPA%20Why%20does%20a%20transformed%20graph%20move%20the%20wrong%20way.pdf

Foster, C. (2026). Short video explanations. Mathematics in School, 55(5), 2–4. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Short%20video%20explanations.pdf

Foster, C. (2026). Negative numbers. Teach Secondary, 15(8), 47. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Negative%20numbers.pdf

Foster, C. (2026). Pentacubes. Teach Secondary, 15(7), 37. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Pentacubes.pdf

Foster, C. (2026). Teaching the big ideas in school mathematics. Mathematics in School, 55(4), 10–11. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Teaching%20the%20BIG%20IDEAS%20in%20school%20mathematics.pdf

Foster, C. (2026). Teaching the multiplication tables multiplicatively. Primary Mathematics, 30(3), 6–9. https://www.foster77.co.uk/Foster,%20Primary%20Mathematics,%20Teaching%20the%20multiplication%20tables%20multiplicatively.pdf

Foster, C. (2026). Nets and dice. Teach Secondary, 15(6), 43. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Nets%20and%20dice.pdf

Foster, C. (2026). Transformations of graphs. Teach Secondary, 15(5), 43. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Transforming%20graphs.pdf

Foster, C. (2026). Reasons to be cheerful. Teach Secondary, 15(5), 22–23. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Reasons%20to%20be%20cheerful.pdf

Foster, C. (2026). When do fractions simplify? Teach Secondary, 15(4), 74. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20When%20do%20fractions%20simplify.pdf

Foster, C. (2026). Beyond the serve. Teach Secondary, 15(4), 12–13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Beyond%20the%20serve.pdf

Foster, C. (2026). Variance and standard deviation. Teach Secondary, 15(3), 72. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Variance%20and%20standard%20deviation.pdf

Foster, C. (2026). Random-walk plots. Teach Secondary, 15(2), 72. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Random-walk%20plots.pdf

Foster, C. (2026). Compass constructions are not methods. Mathematics in School, 55(2), 10–14. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Compass%20constructions%20are%20not%20methods.pdf

Shore, C., Foster, C., & Francome, T. (2026). Empty number lines for solving linear equations. Mathematics in School, 55(1), 10–17. https://www.foster77.co.uk/Shore%20et%20al.,%20Mathematics%20in%20School,%20Empty%20number%20lines%20for%20solving%20linear%20equations.pdf

Foster, C. (2026). Solving simultaneous equations. Teach Secondary, 15(1), 72. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Solving%20simultaneous%20equations.pdf

Foster, C. (2026). We all make mistakes. Teach Secondary, 15(1), 34–35. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20We%20all%20make%20mistakes.pdf

Foster, C. (2025). Appreciating the second-derivative test. Scottish Mathematical Council Journal, 55, 70–71. https://www.foster77.co.uk/Foster,%20Scottish%20Mathematical%20Council%20Journal,%20Appreciating%20the%20second-derivative%20test.pdf

Foster, C. (2025). Logarithms and their bases. Scottish Mathematical Council Journal, 55, 68–69. https://www.foster77.co.uk/Foster,%20Scottish%20Mathematical%20Council%20Journal,%20Logarithms%20and%20their%20bases.pdf

Foster, C. (2025). Playing with asymptotes. Scottish Mathematical Council Journal, 55, 62–67. https://www.foster77.co.uk/Foster,%20Scottish%20Mathematical%20Council%20Journal,%20Playing%20with%20asymptotes.pdf

Francome, T., & Foster, C. (2025). When can things be added together? Mathematics Teaching, 298, 22–24. https://www.foster77.co.uk/Francome%20&%20Foster,%20Mathematics%20Teaching,%20When%20can%20things%20be%20added%20together.pdf

Foster, C. (2025). Questions pupils ask: How can probability density be greater than 1? Mathematics in School, 54(5), 22–23. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20QPA%20How%20can%20probability%20density%20be%20greater%20than%201.pdf

Foster, C. (2025). Questions pupils ask: Why do \(p\) values need to include more extreme possibilities? Mathematics in School, 54(5), 16–19. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20QPA%20Why%20do%20p%20values%20need%20to%20include%20more%20extreme%20possibilities.pdf

Foster, C. (2025). Independent events and inequalities. Mathematics in School, 54(5), 10–11. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Independent%20events%20and%20inequalities.pdf

Foster, C. (2025). Linear sequences. Teach Secondary, 14(8), 87. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Linear%20sequences.pdf

Foster, C. (2025). Nobody should be perfect. Teach Secondary, 14(8), 38–39. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Nobody%20should%20be%20perfect.pdf

Foster, C. (2025). Tech, teaching and trust. Teach Secondary, 14(7), 24–25. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Tech,%20teaching%20and%20trust.pdf

Foster, C. (2025). Proportionality. Teach Secondary, 14(7), 69. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Proportionality.pdf

Foster, C. (2025). Questions pupils ask: Does a remote-controlled toy car violate Newton’s laws of motion? Mathematics in School, 54(4), 24–28. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20QPA%20Does%20a%20remote-controlled%20toy%20car%20violate%20Newton's%20laws%20of%20motion.pdf

Moeller, K., O’Brien, D., & Foster, C. (2025). Which way should your number line go? Primary Mathematics, 29(3), 23–25. https://www.foster77.co.uk/Moeller%20et%20al.,%20Primary%20Mathematics,%20Which%20way%20should%20your%20number%20line%20go.pdf

Foster, C. (2025). Being flexible about division. Primary Mathematics, 29(3), 3–6. https://www.foster77.co.uk/Foster,%20Primary%20Mathematics,%20Being%20flexible%20about%20division.pdf

Foster, C. (2025). Choosing choice. Teach Secondary, 14(6), 80–81. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Choosing%20choice.pdf

Foster, C. (2025). Estimating volume. Teach Secondary, 14(6), 55. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Estimating%20Volume.pdf

Foster, C. (2025). Do I have your attention…? Teach Secondary, 14(5), 22–23. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Do%20I%20have%20your%20attention.pdf

Foster, C. (2025). Angles in the same segment. Teach Secondary, 14(5), 69. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Angles%20in%20the%20same%20segment.pdf

Foster, C. (2025, June). Ask the expert: Educating mathematically exceptional children. Preneur World Magazine, 38–39. https://www.preneur-world.com/educating-mathematically-exceptional-children/ pdf

Foster, C. (2025). You are not an imposter. Teach Secondary, 14(4), 70–71. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20You%20are%20not%20an%20imposter.pdf

Foster, C. (2025). Standard form with numbers less than 1. Teach Secondary, 14(4), 69. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Standard%20form%20with%20numbers%20less%20than%201.pdf

Foster, C. (2025). Questions pupils ask: Is infinity a number? Mathematics in School, 54(3), 20–21. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20QPA%20Is%20infinity%20a%20number.pdf

Foster, C. (2025). Converting compound units. Teach Secondary, 14(3), 69. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Converting%20compound%20units.pdf

Foster, C. (2025). Why mastery matters. Teach Secondary, 14(3), 22–23. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Why%20mastery%20matters.pdf

Foster, C. (2025). The amber traffic light. Mathematics in School, 54(2), 10–11. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20The%20amber%20traffic%20light.pdf

Foster, C. (2025). Alternatives to atomisation. Mathematics Teaching, 295, 37–41. https://www.foster77.co.uk/Foster,%20Mathematics%20Teaching,%20Alternatives%20to%20atomisation.pdf

Foster, C. (2025). Venn diagrams for probability. Teach Secondary, 14(2), 67. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Venn%20diagrams%20for%20probability.pdf

Foster, C. (2025). Ready for anything. Teach Secondary, 14(2), 22–23. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Ready%20for%20anything.pdf

Foster, C. (2025). Rationalising all kinds of denominators. Mathematics in School, 54(1), 13–15. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Rationalising%20all%20kinds%20of%20denominators.pdf

Foster, C. (2025). Lower and upper bounds. Teach Secondary, 14(1), 21. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Lower%20and%20upper%20bounds.pdf

Foster, C. (2025). Say it again. Teach Secondary, 14(1), 66–67. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Say%20it%20again.pdf

Foster, C. (2024). Embrace your flaws. Teach Secondary, 13(8), 56–57. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Embrace%20your%20flaws.pdf

Foster, C. (2024). Bar charts versus pie charts. Teach Secondary, 13(8), 10. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Bar%20charts%20versus%20pie%20charts.pdf

Foster, C. (2024). Questions pupils ask: Why aren’t square roots additive? Mathematics in School, 53(5), 29–31. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20QPA%20Why%20aren't%20square%20roots%20additive.pdf

Foster, C. (2024). Terminal digits and prime numbers. Mathematics in School, 53(5), 8–9. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Terminal%20digits%20and%20prime%20numbers.pdf

Foster, C. (2024). Having fun being wrong. Mathematics Teaching, 293, 23. https://www.foster77.co.uk/Foster,%20Mathematics%20Teaching,%20Having%20fun%20being%20wrong.pdf

Foster, C. (2024). Know your limits. Teach Secondary, 13(7), 34–35. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Know%20your%20limits.pdf

Foster, C. (2024). Adding and subtracting numbers in standard form. Teach Secondary, 13(7), 21. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Adding%20and%20subtracting%20numbers%20in%20standard%20form.pdf

Foster, C. (2024). Speed calculations. Teach Secondary, 13(6), 55. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Speed%20calculations.pdf

Foster, C. (2024). When good is better than perfect. Teach Secondary, 13(5), 22–23. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20When%20good%20is%20better%20than%20perfect.pdf

Foster, C. (2024). Mixed numbers when combining fractions. Teach Secondary, 13(5), 55. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Mixed%20numbers%20when%20combining%20fractions.pdf

Foster, C. (2024). Inequality signs turning round. Teach Secondary, 13(4), 21. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Inequality%20signs%20turning%20round.pdf

Foster, C. (2024). Go below the surface. Teach Secondary, 13(4), 68–69. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Go%20below%20the%20surface.pdf

Foster, C., Francome, T., & Shore, C. (2024). Trigonometry without SOHCAHTOA. Mathematics in School, 53(3), 8–11. https://www.foster77.co.uk/Foster,%20Francome%20&%20Shore,%20Mathematics%20in%20School,%20Trigonometry%20without%20SOHCAHTOA.pdf

Foster, C. (2024). Expanding pairs of brackets. Teach Secondary, 13(3), 21. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Expanding%20pairs%20of%20brackets.pdf

Foster, C. (2024). Failing to see both sides. Mathematics Teaching, 290, 10–11. https://www.foster77.co.uk/Foster,%20Mathematics%20Teaching,%20Failing%20to%20see%20both%20sides.pdf

Foster, C. (2024). The power of framing. Teach Secondary, 13(2), 52–53. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20The%20power%20of%20framing.pdf

Foster, C. (2024). Trigonometry in right-angled triangles. Teach Secondary, 13(2), 21. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Trigonometry%20in%20right-angled%20triangles.pdf

Foster, C. (2024). Minimalist approaches to teaching trigonometry. Mathematics in School, 53(2), 20–24. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Minimalist%20approaches%20to%20teaching%20trigonometry.pdf

Foster, C. (2024). In favour of the Euclidean Algorithm. Mathematics in School, 53(1), 24–26. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20In%20favour%20of%20the%20Euclidean%20Algorithm.pdf

Foster, C. (2024). More than a feeling. Teach Secondary, 13(1), 70–71. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20More%20than%20a%20feeling.pdf

Foster, C. (2024). The quadratic formula. Teach Secondary, 13(1), 21. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20The%20quadratic%20formula.pdf (Resource sheet pdf)

Foster, C. (2023). Improving educational design by comparing alternatives. Mathematics Teaching, 289, 14–18. https://www.foster77.co.uk/Foster,%20Mathematics%20Teaching,%20Improving%20educational%20design%20by%20comparing%20alternatives.pdf

Foster, C. (2023). Unconvincing proofs: The sum of a geometric sequence. Scottish Mathematical Council Journal, 53, 62–64. https://www.foster77.co.uk/Foster,%20Scottish%20Mathematical%20Council%20Journal,%20Unconvincing%20proofs%20-%20the%20sum%20of%20a%20geometric%20sequence.pdf

Foster, C. (2023). Perpendicular gradients. Teach Secondary, 12(8), 11. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Perpendicular%20gradients.pdf

Shore, C., Francome, T., & Foster, C. (2023). The sheer delight of shearing. Mathematics in School, 52(4), 32–34. https://www.foster77.co.uk/Shore,%20Francome,%20&%20Foster,%20Mathematics%20in%20School,%20The%20sheer%20delight%20of%20sheering.pdf

Foster, C. (2023). Subtractive solutions. Teach Secondary, 12(7), 46–47. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Subtractive%20solutions.pdf

Foster, C. (2023). Finding the Nth term. Teach Secondary, 12(7), 11. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Finding%20the%20nth%20term.pdf

Foster, C. (2023). Schools of thought. Teach Secondary, 12(6), 42–43. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Schools%20of%20thought.pdf

Foster, C. (2023). Recurring decimals. Teach Secondary, 12(6), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Recurring%20decimals.pdf

Foster, C. (2023). Less is more: Improving by removing. Mathematics Teaching, 287, 7–14. https://www.foster77.co.uk/Foster,%20Mathematics%20Teaching,%20Less%20is%20more.pdf

Foster, C. (2023). Emotional preparation. Teach Secondary, 12(4), 44–45. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Emotional%20preparation.pdf

Foster, C. (2023). Perimeters of sectors. Teach Secondary, 12(4), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Perimeters%20of%20sectors.pdf

Foster, C. (2023). Questions pupils ask: Why do we divide by \(n–1\)? Mathematics in School, 52(3), 20–22. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Why%20do%20we%20divide%20by%20n-1.pdf

Foster, C. (2023). Simultaneous equations. Teach Secondary, 12(3), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Simultaneous%20equations.pdf

Foster, C. (2023). Easy when you know how. Teach Secondary, 12(3), 38–39. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Easy%20when%20you%20know%20how.pdf

Foster, C. (2023). Abolish degrees! Mathematics in School, 52(2), 21–23. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Abolish%20degrees.pdf

Foster, C. (2023). Equilateral triangles within a regular hexagon. Symmetry Plus, 80, 4. https://www.foster77.co.uk/Foster,%20Symmetry%20Plus,%20Equilateral%20triangles%20within%20a%20regular%20hexagon.pdf

Foster, C. (2023). Area and volume scale factors. Teach Secondary, 12(2), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Area%20and%20volume%20scale%20factors.pdf

Foster, C. (2022). Writing articles for professional publications. MA News - The Mathematical Association Newsletter, 180, 1–6. https://www.foster77.co.uk/Foster,%20MA%20News%20February%202023.pdf

Foster, C. (2023). Is there any place for rote learning in mathematics? Mathematics Teaching, 285, 20–22. https://www.foster77.co.uk/Foster,%20Mathematics%20Teaching,%20Is%20there%20any%20place%20for%20rote%20learning%20in%20mathematics.pdf

Foster, C. (2023). Learning isn’t linear. Teach Secondary, 12(1), 50–51. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Learning%20isn't%20linear.pdf

Foster, C. (2023). Significant figures. Teach Secondary, 12(1), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Significant%20figures.pdf

Foster, C. (2022). Unconvincing proofs: The harmonic series. Scottish Mathematical Council Journal, 52, 76–78. https://www.foster77.co.uk/Foster,%20Scottish%20Mathematical%20Council%20Journal,%20Unconvincing%20proofs%20-%20the%20harmonic%20series.pdf

Foster, C. (2022). Converting recurring decimals to fractions. Scottish Mathematical Council Journal, 52, 68–70. https://www.foster77.co.uk/Foster,%20Scottish%20Mathematical%20Council%20Journal,%20Converting%20recurring%20decimals%20to%20fractions.pdf

Foster, C. (2022). Compass constructions are not methods. Scottish Mathematical Council Journal, 52, 54–58. https://www.foster77.co.uk/Foster,%20Scottish%20Mathematical%20Council%20Journal,%20Compass%20constructions%20are%20not%20methods.pdf

Foster, C. (2022). Factor puzzles. Symmetry Plus, 79, 4–5. https://www.foster77.co.uk/Foster,%20Symmetry%20Plus,%20Factor%20puzzles.pdf

Foster, C. (2022). Leading professional development sessions. MA News - The Mathematical Association Newsletter, 179, 1–4. https://www.foster77.co.uk/Foster,%20MA%20News%20October%202022.pdf

Foster, C. (2022). Originality is overrated. Teach Secondary, 11(8), 30–31. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Originality%20is%20overrated.pdf

Foster, C. (2022). Completing the square. Teach Secondary, 11(8), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Completing%20the%20square.pdf (Resource sheet pdf)

Foster, C. (2022). Making sense of proof by contradiction. Mathematics in School, 51(5), 32–35. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Making%20sense%20of%20proof%20by%20contradiction.pdf (Reprinted from Scottish Mathematical Council Journal: Original article published 2021)

Foster, C. (2022). The floor and ceiling functions. Mathematics in School, 51(5), 30–31. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20The%20floor%20and%20ceiling%20functions.pdf

Foster, C. (2022). Thinking hard about easy content: Odd and even functions. Mathematics in School, 51(5), 28–29. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Thinking%20hard%20about%20easy%20content%20-%20Odd%20and%20even%20functions.pdf

Foster, C., Francome, T., Hewitt, D., & Shore, C. (2022). What is a fraction? Mathematics in School, 51(5), 25–27. https://www.foster77.co.uk/Foster%20et%20al.,%20Mathematics%20in%20School,%20What%20is%20a%20fraction.pdf

Foster, C. (2022). Are words sometimes better than formulae? Mathematics in School, 51(5), 12–14. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Are%20words%20sometimes%20better%20than%20formulae.pdf

Foster, C. (2022). Connecting things up coherently. Mathematics in School, 51(5), 8–11. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Connecting%20things%20up%20coherently.pdf

Foster, C. (2022). The directionality of the equals sign. Mathematics in School, 51(5), 6–7. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20The%20directionality%20of%20the%20equals%20sign.pdf

Foster, C. (2022). Starting with completing the square. Mathematics in School, 51(5), 2–5. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Starting%20with%20completing%20the%20square.pdf

Foster, C. (2022). Is it wrong to want to be liked? Teach Secondary, 11(7), 48–49. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Is%20it%20wrong%20to%20want%20to%20be%20liked.pdf

Foster, C. (2022). Adding surds. Teach Secondary, 11(7), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Adding%20surds.pdf

Foster, C., & Francome, T. (2022). Diagrams not drawn accurately. Mathematics in School, 51(4), 20–22. https://www.foster77.co.uk/Foster%20&%20Francome,%20Mathematics%20in%20School,%20Diagrams%20not%20drawn%20accurately.pdf

Foster, C. (2022). Crossing out. Mathematics in School, 51(4), 6–7. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Crossing%20out.pdf

Foster, C. (2022). Home truths. Teach Secondary, 11(6), 32–33. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Home%20truths.pdf

Foster, C. (2022). A clear account of events. Teach Secondary, 11(6), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20A%20clear%20account%20of%20events.pdf (Resource sheet pdf)

Foster, C. (2022). A journey from pupil to researcher. MA News - The Mathematical Association Newsletter, 178, 1–4. https://www.foster77.co.uk/Foster,%20MA%20News%20June%202022.pdf

Foster, C. (2022). The trouble with groupwork. Teach Secondary, 11(5), 70–71. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20The%20trouble%20with%20groupwork.pdf

Foster, C. (2022). Dividing fractions. Teach Secondary, 11(5), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Dividing%20fractions.pdf

Foster, C. (2022). The usual suspects? Teach Secondary, 11(4), 62–63. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20The%20usual%20suspects.pdf

Foster, C. (2022). Pythagoras’s Theorem. Teach Secondary, 11(4), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Pythagoras's%20Theorem.pdf (Resource sheet pdf)

Francome, T., & Foster, C. (2022). Plenary - or just ponder? Mathematics Teaching, 281, 19–21. https://www.foster77.co.uk/Francome%20&%20Foster,%20Plenary%20or%20ponder.pdf

Foster, C. (2022). Choosing the best proofs. Mathematics in School, 51(3), 2–7. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Choosing%20the%20best%20proofs.pdf

Foster, C. (2022). Must feedback always be constructive? Teach Secondary, 11(3), 40–41. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Must%20feedback%20always%20be%20constructive.pdf

Foster, C. (2022). Factors and multiples. Teach Secondary, 11(3), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Factors%20and%20multiples.pdf

Foster, C. (2022). Meet the next MA President - Colin Foster. MA News - The Mathematical Association Newsletter, 177, 6. https://www.foster77.co.uk/Foster,%20MA%20News,%20February%202022,%20Meet%20the%20next%20MA%20President.pdf

Foster, C. (2022). Exterior angles. Teach Secondary, 11(2), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Exterior%20angles.pdf (Resource sheet pdf)

Foster, C. (2022). Methods that are just mental clutter. Mathematics in School, 51(2), 20–22. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Methods%20that%20are%20just%20mental%20clutter.pdf

Foster, C. (2022). Getting multiplication the right way round. Mathematics in School, 51(2), 16–17. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Getting%20multiplication%20the%20right%20way%20round.pdf

Foster, C. (2022). Listening is slow, reading is fast. Teach Secondary, 11(1), 72–73. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Listening%20is%20slow,%20reading%20is%20fast.pdf

Foster, C. (2022). What is an angle? Teach Secondary, 11(1), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20What%20is%20an%20angle.pdf

Foster, C. (2022). Giving everything a twist. Mathematics in School, 51(1), 24–25. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Giving%20everything%20a%20twist.pdf

Foster, C. (2021). Making sense of proof by contradiction. Scottish Mathematical Council Journal, 51, 74–77. https://www.foster77.co.uk/Foster,%20Scottish%20Mathematical%20Council%20Journal,%20Making%20sense%20of%20proof%20by%20contradiction.pdf

Foster, C. (2021). Identity crisis. Scottish Mathematical Council Journal, 51, 36–37. https://www.foster77.co.uk/Foster,%20Scottish%20Mathematical%20Council%20Journal,%20Identity%20crisis.pdf

Foster, C. (2021). Multiplying makes things bigger. Teach Secondary, 10(8), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Multiplying%20makes%20things%20bigger.pdf

Foster, C. (2021). Assuming the worst is often for the best. Teach Secondary, 10(7), 23. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Assuming%20the%20worst%20is%20often%20for%20the%20best.pdf

Foster, C. (2021). Symmetry. Teach Secondary, 10(7), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Symmetry.pdf

Foster, C. (2021). Area and perimeter. Teach Secondary, 10(6), 13. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Area%20and%20perimeter.pdf

Foster, C. (2021). First things first. Teach Secondary, 10(6), 82–83. https://www.teachwire.net/news/early-career-teachers/ pdf

Foster, C. (2021). Questions pupils ask: What are ‘like terms’? Mathematics in School, 50(4), 20–21. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20What%20are%20'like%20terms'.pdf

Foster, C. (2021). Problem solving and prior knowledge. Mathematics in School, 50(4), 6–8. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Problem%20solving%20and%20prior%20knowledge.pdf

Foster, C. (2021). “But I’m no good…”. Teach Secondary, 10(5), 58–59. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20But%20I'm%20no%20good.pdf

Foster, C. (2021). Understanding indices. Teach Secondary, 10(5), 11. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Understanding%20indices.pdf

Foster, C. (2021). Adding fractions. Teach Secondary, 10(4), 11. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Adding%20fractions.pdf

Foster, C. (2021). Trapezium artist: Some thoughts on the formula for the area of a trapezium. Mathematics in School, 50(3), 4–5. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Trapezium%20artist%20reprinted.pdf (Reprinted: Original article published 2004)

Foster, C. (2021). Quotative and partitive models of division. Mathematics in School, 50(3), 24–25. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Quotative%20and%20partitive%20models%20of%20division.pdf

Foster, C. (2021). What’s in a name? Teach Secondary, 10(3), 11. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20What's%20in%20a%20name.pdf

Foster, C. (2021). Percentage change. Teach Secondary, 10(2), 11. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Percentage%20change.pdf

Foster, C. (2021). On hating formula triangles. Mathematics in School, 50(1), 31–32. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20On%20hating%20formula%20triangles.pdf

Foster, C. (2021). In a spin. Teach Secondary, 10(1), 11. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20In%20a%20spin.pdf

Foster, C. (2020). Half of the sum of the others. Scottish Mathematical Council Journal, 50, 47–48. https://www.foster77.co.uk/Foster,%20SMCJ,%20Half%20of%20the%20sum%20of%20the%20others.pdf

Foster, C. (2020). Tailoring the examples to the method. Scottish Mathematical Council Journal, 50, 34–35. https://www.foster77.co.uk/Foster,%20SMCJ,%20Tailoring%20the%20examples%20to%20the%20method.pdf

Foster, C. (2020). Number snakes. Teach Secondary, 9(8), 70–71. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Number%20snakes.pdf

Foster, C. (2020). Questions pupils ask: Differentiating inverse trigonometric functions. Mathematics in School, 49(5), 10–12. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Differentiating%20inverse%20trig%20functions.pdf

Foster, C. (2020). Combining square numbers. Teach Secondary, 9(7), 94–95. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Combining%20square%20numbers.pdf

Foster, C. (2020). A slice of the pie. Teach Secondary, 9(6), 102–103. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20A%20slice%20of%20the%20pie.pdf

Foster, C., & Ollerton, M. (2020). Mathematical white lies. Mathematics Teaching, 272, 24–25. https://www.foster77.co.uk/MT272Foster&OllertonMathematical_white_lies.pdf

Foster, C. (2020). Revisiting ‘Four 4s’. Mathematics in School, 49(3), 22–23. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Revisiting%20Four%204s.pdf

Foster, C. (2020). Trusting in patterns. Mathematics in School, 49(3), 17–19. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Trusting%20in%20patterns.pdf

Foster, C. (2020). Counting out. Teach Secondary, 9(3), 70–71. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Counting%20out.pdf (Spreadsheet resource xlsx)

Foster, C. (2020). Twice as hot? Mathematics in School, 49(2), 28–29. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Twice%20as%20hot.pdf

Foster, C., & Baldry, F. (2020). Blink, and it’s gone! Mathematics Teaching, 270, 12–13. https://www.foster77.co.uk/MT270%20Foster&Baldry%20Blink%20and%20it's%20gone.pdf

Foster, C. (2020). The tethered goat. Teach Secondary, 9(2), 90–91. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20The%20tethered%20goat.pdf

Foster, C. (2020). Stop planning lessons! Teach Secondary, 9(1), 80–81. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Stop%20planning%20lessons.pdf

Foster, C. (2020). Statistical puzzler. Teach Secondary, 9(1), 84–85. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Statistical%20puzzler.pdf

Foster, C. (2019). Alternative vouchers. Teach Secondary, 8(8), 90–91. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Alternative%20vouchers.pdf (Resource sheet pdf)

Seino, T., & Foster, C. (2019). Why the details matter: Learning from Japanese Kyouzai kenkyuu. Mathematics in School, 48(5), 2–8. https://www.foster77.co.uk/Seino%20&%20Foster,%20Mathematics%20in%20School,%20Why%20the%20details%20matter.pdf

Foster, C. (2019). What’s your style, sir? Teach Secondary, 8(7), 22–23. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20What's%20your%20style,%20sir.pdf

Foster, C. (2019). Sine language. Teach Secondary, 8(7), 92–93. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Sine%20language.pdf

Foster, C. (2019). Questions pupils ask: What counts as a random number? Mathematics in School, 48(4), 30–31. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20What%20counts%20as%20a%20random%20number.pdf

Foster, C. (2019). Spider on a cuboid. Teach Secondary, 8(6), 116–117. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Spider%20on%20a%20cuboid.pdf

Foster, C. (2019). Doing it with understanding. Mathematics Teaching, 267, 8–10. https://www.foster77.co.uk/MT26703.pdf

Foster, C. (2019). Spotting sequences. Teach Secondary, 8(5), 94–95. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Spotting%20sequences.pdf

Foster, C. (2019). Trapezia acts. Teach Secondary, 8(4), 82–83. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Trapezia%20acts.pdf

Foster, C. (2019). Armchair responses. Mathematics in School, 48(3), 26–27. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Armchair%20responses.pdf

Foster, C. (2019). Box plots. Teach Secondary, 8(3), 102–103. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Box%20plots.pdf (Resource sheet pdf) (Spreadsheet resource xlsx)

Foster, C. (2019). The fundamental problem with teaching problem solving. Mathematics Teaching, 265, 8–10. https://www.foster77.co.uk/MT26503.pdf

Foster, C. (2019). Missing the point. Teach Secondary, 8(2), 86–87. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Missing%20the%20point.pdf (Resource sheet pdf)

Foster, C. (2019). Questions pupils ask: Why can’t it be distance plus time? Mathematics in School, 48(1), 15–17. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Why%20can't%20it%20be%20distance%20plus%20time.pdf

Foster, C. (2019). Knowing the unknowns. Teach Secondary, 8(1), 86–87. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Knowing%20the%20unknowns.pdf

Foster, C. (2018). Almost zero. Teach Secondary, 7(8), 84–85. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Almost%20zero.pdf

Foster, C. (2018). The converse of Pythagoras’ Theorem. Mathematics in School, 47(5), 40–42. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20The%20converse%20of%20Pythagoras'%20theorem.pdf

Hodgen, J., & Foster, C. (2018). What’s so hard about algebra? Mathematics in School, 47(5), 6–7. https://www.foster77.co.uk/Hodgen%20&%20Foster,%20Mathematics%20in%20School,%20What's%20so%20hard%20about%20algebra.pdf

Foster, C. (2018). Robot rendezvous. Teach Secondary, 7(7), 86–87. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Robot%20rendezvous.pdf

Foster, C. (2018). Stop the clock! Symmetry Plus, 67, 18. https://www.foster77.co.uk/Foster,%20Symmetry%20Plus,%20Stop%20the%20clock.pdf (For answers, click here.)

Foster, C. (2018). Take your seat. Symmetry Plus, 67, 6. https://www.foster77.co.uk/Foster,%20Symmetry%20Plus,%20Take%20your%20seat.pdf

Foster, C. (2018). Two spinners. Teach Secondary, 7(6), 114–115. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Two%20spinners.pdf

Foster, C. (2018). Questions pupils ask: What is the formula for factorial? Mathematics in School, 47(4), 40–41. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20QPA%20What%20is%20the%20formula%20for%20factorial.pdf

Hodgen, J., & Foster, C. (2018). Calculators - friend or foe? Mathematics Teaching, 262, 18. https://www.foster77.co.uk/MT26207.pdf

Foster, C. (2018). Beat the calculator. Teach Secondary, 7(5), 86–87. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Beat%20the%20calculator.pdf

Foster, C. (2018). Questions pupils ask: Is calculus exact? Mathematics in School, 47(3), 36–38. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Is%20calculus%20exact.pdf

Foster, C. (2018). Boxing clever. Teach Secondary, 7(4), 84–85. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Boxing%20clever.pdf

Foster, C. (2018). [Review of the book Practising Mathematics, by T. Francome & D. Hewitt]. Mathematics Teaching, 261, 48. https://www.foster77.co.uk/MT261_-_Book_review.pdf

Foster, C. (2018). Surviving in the desert. Teach Secondary, 7(3), 88–89. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Surviving%20in%20the%20desert.pdf (Resource sheet pdf)

Foster, C. (2018). [Review of the book Mathematics Rebooted, by L. Alcock]. Mathematics in School, 47(2), 57–58. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Review%20of%20Alcock%20Mathematics%20Rebooted.pdf

Foster, C. (2018). Proportionality with Malcolm. Mathematics in School, 47(2), 34–35. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Proportionality%20with%20Malcolm.pdf

Foster, C. (2018). Editorial: Special issue. Mathematics in School, 47(2), 1. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Editorial%20for%20Swan%20Special%20Issue.pdf

Foster, C., Hodgen, J., & Küchemann, D. (2018). Defining a rhombus. Mathematics Teaching, 260, 31. https://www.foster77.co.uk/MT26012-5jF4FkXo.pdf

Foster, C., & Inglis, M. (2018). How do you describe mathematics tasks? Mathematics Teaching, 260, 18–20. https://www.foster77.co.uk/MT26007-XaM4aADR.pdf

Foster, C. (2018). Five triangles. Teach Secondary, 7(2), 30–31. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Five%20triangles.pdf (Resource sheet pdf)

Foster, C. (2018). Questions pupils ask: Is i irrational? Mathematics in School, 47(1), 31–33. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Is%20i%20irrational.pdf

Foster, C. (2017). Trigonometry without tears. Teach Secondary, 7(1), 30–31. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Trigonometry%20without%20tears.pdf (Resource sheet pdf)

Foster, C. (2017). Get your bearings. Teach Secondary, 6(8), 32–33. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Get%20your%20bearings.pdf (Resource sheet pdf and solution sheet pdf)

Foster, C. (2017). The guessing game. Teach Secondary, 6(8), 85. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20The%20guessing%20game.pdf

Foster, C. (2017). Questions pupils ask: What is the net for a parallelepiped? Mathematics in School, 46(5), 38–39. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20What%20is%20the%20net%20for%20a%20parallelepiped.pdf

Foster, C., & Martin, D. (2017). Playing with dice. Mathematics in School, 46(5), 26–27. https://www.foster77.co.uk/Foster%20&%20Martin,%20Mathematics%20in%20School,%20Playing%20with%20dice.pdf

Foster, C. (2017). Just four numbers. Teach Secondary, 6(7), 36–37. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Just%20four%20numbers.pdf

Foster, C. (2017). Buying coffee. Symmetry Plus, 64, 19. https://www.foster77.co.uk/Foster,%20Symmetry%20Plus,%20Buying%20Coffee.pdf

Foster, C. (2017). Questions pupils ask: Can I just move the decimal point? Mathematics in School, 46(4), 39. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Can%20I%20just%20move%20the%20decimal%20point.pdf

Foster, C. (2017). Always up to? Mathematics in School, 46(4), 30–31. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Always%20up%20to.pdf

Foster, C. (2017). A fitting challenge. Teach Secondary, 6(6), 48–49. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20A%20fitting%20challenge.pdf (Full lesson plan)

Foster, C. (2017). Making quadratics. Teach Secondary, 6(5), 31. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Making%20quadratics.pdf (Full lesson plan and resource sheet pdf)

Foster, C. (2017). Mathematical etudes. NRICH. https://nrich.maths.org/articles/mathematical-etudes

Foster, C. (2017). Pink paint. Teach Secondary, 6(4), 32. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Mixing%20paints.pdf (Full lesson plan [pdf])

Foster, C. (2017). Reaching the 100th square. Mathematics in School, 46(3), 32–34. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Reaching%20the%20100th%20square.pdf

Foster, C. (2017). Counting zeroes. Symmetry Plus, 63, 18. https://www.foster77.co.uk/Foster,%20Symmetry%20Plus,%20Counting%20zeroes.pdf

Foster, C. (2017). Hit ten! Teach Secondary, 6(3), 37. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Hit%20ten.pdf (Full lesson plan [pdf] and resource sheet pdf)

Foster, C. (2017). Newspaper pages. Teach Secondary, 6(2), 36–38. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Newspaper%20pages.pdf

Foster, C. (2017). Inferring sample size. Mathematics in School, 46(2), 32–33. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Inferring%20sample%20size.pdf

Foster, C. (2017). Surprise, surprise! Teach Secondary, 6(1), 42–44. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Surprise%20surprise.pdf

Foster, C. (2017). Carrying your provisions. Mathematics in School, 46(1), 30. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Carrying%20your%20provisions.pdf

Foster, C. (2016). Mind your head! Teach Secondary, 5(8), 30–32. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Mind%20your%20head.pdf

Foster, C. (2016). Family negotiations. Mathematics in School, 45(5), 10–11. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Family%20Negotiations.pdf

Foster, C. (2016). Sports centre. Teach Secondary, 5(7), 29–31. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Sports%20Centre.pdf (Resource sheets: bar charts pdf; main task sheets: pdf)

Foster, C. (2016). Clock watching. Symmetry Plus, 61, 7. https://www.foster77.co.uk/Foster,%20Symmetry%20Plus,%20Clock%20Watching.pdf

Foster, C. (2016). Rolls of the dice. Teach Secondary, 5(6), 43–45. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Rolls%20of%20the%20dice.pdf (Spreadsheet resource xlsx)

Foster, C. (2016). Making products. Teach Secondary, 5(5), 31–33. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Making%20products.pdf

Foster, C. (2016). Abdul and Bella. Symmetry Plus, 60, 4. https://www.foster77.co.uk/Foster,%20Symmetry%20Plus,%20Abdul%20and%20Bella.pdf

Foster, C. (2016). Hopping along. Teach Secondary, 5(4), 31–33. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Hopping%20along.pdf (Resource sheet pdf)

Foster, C. (2016). Questions pupils ask: Why isn’t 1 a prime number? Mathematics in School, 45(3), 12–13. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Why%20isn't%201%20a%20prime%20number.pdf

Foster, C. (2016). Confidence and ‘negative’ marking. Mathematics Teaching, 251, 11–13. https://www.foster77.co.uk/MT251-16-04.pdf

Foster, C. (2016). All square. Teach Secondary, 5(3), 33–35. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20All%20Square.pdf

Foster, C. (2016). Thirty factors. Mathematics in School, 45(2), 25–27. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Thirty%20Factors.pdf

Foster, C. (2016). The simple life. Teach Secondary, 5(2), 31–33. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20The%20simple%20life.pdf (Resource sheet pdf; NRICH version: https://nrich.maths.org/problems/simple-life)

Foster, C. (2016). Sums of pairs. Symmetry Plus, 59, 14–16. https://www.foster77.co.uk/Foster,%20Symmetry%20Plus,%20Sums%20of%20Pairs.pdf

Foster, C. (2016). Painting a wall. Teach Secondary, 5(1), 29–31. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Painting%20a%20wall.pdf (Resource sheet pdf, docx)

Foster, C. (2015). Plus-minus graphs. Scottish Mathematical Council Journal, 44, 52–53. https://www.foster77.co.uk/Foster,%20Scottish%20Mathematical%20Council%20Journal,%20Plus-Minus%20Graphs.pdf

Foster, C. (2015). Where does the third come from? Scottish Mathematical Council Journal, 44, 59–62. https://www.foster77.co.uk/Foster,%20Scottish%20Mathematical%20Council%20Journal,%20Where%20does%20the%20third%20come%20from.pdf

Foster, C. (2015). Clock watching. Teach Secondary, 4(8), 31–32. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Clock%20Watching.pdf (Spreadsheet resource xls)

Foster, C. (2015). Questions pupils ask: Where does the third come from? Mathematics in School, 44(5), 13–16. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Where%20does%20the%20third%20come%20from.pdf (Resource sheet pdf)

Foster, C. (2015). Symmetry combinations. Teach Secondary, 4(7), 43–45. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Symmetry%20Combinations.pdf (Resource sheet pdf)

Foster, C. (2015). Observing other subjects. Mathematics Teaching, 248, 21. https://www.foster77.co.uk/MT248-15-08.pdf

Foster, C. (2015). The meaning of the mean. Teach Secondary, 4(6), 37–39. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20The%20Meaning%20of%20the%20Mean.pdf (Resource sheet pdf)

Foster, C., Ollerton, M., & Watson, A. (2015). Knowing and not knowing how a task for use in a mathematics classroom might develop. Mathematics Teaching, 247, 5–8. https://www.foster77.co.uk/MT247-14-01.pdf

Foster, C. (2015). The shortest way. Teach Secondary, 4(5), 33–35. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20The%20Shortest%20Way.pdf (Resource sheet pdf)

Foster, C. (2015). Shaping up. Teach Secondary, 4(4), 33–35. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Shaping%20Up.pdf (Resource sheet pdf)

Foster, C. (2015). Crossing lines. Teach Secondary, 4(3), 31–33. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Crossing%20Lines.pdf

Foster, C. (2015). Prime suspects. Teach Secondary, 4(2), 41–43. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Prime%20Suspects.pdf (Resource sheet pdf and completed sheet pdf)

Foster, C. (2015). Repeated rotations. Teach Secondary, 4(1), 35–37. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Repeated%20rotations.pdf (Resource sheet pdf and Geogebra files ggb, ggb)

Foster, C. (2015). Questions pupils ask: Doubly positive. Mathematics in School, 44(2), 34–35. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Doubly%20Positive.pdf

Foster, C. (2015). Fitting shapes inside shapes: Closed but provocative questions. Mathematics in School, 44(2), 12–14. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Fitting%20shapes%20inside%20shapes.pdf

Foster, C. (2014). The power of puzzles. Teach Secondary, 3(8), 34–35. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20The%20Power%20of%20Puzzles.pdf (Resource sheet pdf)

Foster, C. (2014). What’s the deal? Teach Secondary, 3(7), 34–35. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20What's%20The%20Deal.pdf (Resource sheet pdf)

Foster, C. (2014). Teaching to the test – a parable. Mathematics Teaching, 242, 33. https://www.foster77.co.uk/MT242-14-12.pdf

Foster, C. (2014). Sweet solutions. Teach Secondary, 3(6), 46–47. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Sweet%20solutions.pdf

Griffiths, J., & Foster, C. (2014). “Bath mat” versus “bar mat”. Mathematics Teaching, 241, 18–21. https://www.foster77.co.uk/MT241-14-06.pdf

Foster, C. (2014). Sum fractions. Teach Secondary, 3(5), 48–49. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Sum%20fractions.pdf (NRICH version: https://nrich.maths.org/problems/almost-one)

Foster, C. (2014). Angle chasing. Teach Secondary, 3(4), 40–41. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Angle%20Chasing.pdf (Resource sheets pdf)

Foster, C. (2014). Mathematical fluency without drill and practice. Mathematics Teaching, 240, 5–7. https://www.foster77.co.uk/MT240-14-01.pdf

Foster, C. (2014). Being inclusive. Mathematics in School, 43(3), 12–13. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Being%20inclusive.pdf

Foster, C. (2014). Going with the flow. Teach Secondary, 3(3), 43–45. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Going%20with%20the%20flow.pdf (Resource sheet pdf)

Foster, C. (2014). Questions pupils ask: Why isn’t pi a whole number? Mathematics in School, 43(2), 37–38. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Why%20isn't%20pi%20a%20whole%20number.pdf

Foster, C. (2014). Simultaneous inequalities. Mathematics in School, 43(2), 34–35. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Simultaneous%20Inequalities.pdf

Foster, C. (2014). Arithmagons. Teach Secondary, 3(2), 57–59. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Arithmagons.pdf

Foster, C. (2014). Being mean about the mean. Mathematics in School, 43(1), 32–33. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Being%20mean%20about%20the%20mean.pdf

Foster, C. (2013). Staying on the page. Teach Secondary, 3(1), 57–59. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Staying%20on%20the%20Page.pdf (Resource sheet pdf)

Foster, C. (2013). Cancelling out. Teach Secondary, 2(8), 47–49. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Cancelling%20Out.pdf (Resource sheet pdf, doc)

Foster, C. (2013). Coining queries. Teach Secondary, 2(7), 25–27. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Coining%20Queries.pdf

Foster, C. (2013). Plenty of lolly. Teach Secondary, 2(6), 49–51. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Plenty%20of%20Lolly.pdf

Foster, C. (2013). Growing shapes. Teach Secondary, 2(5), 30–32. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Growing%20Shapes.pdf

Foster, C. (2013). Rich pickings. Teach Secondary, 2(4), 32–34. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Rich%20Pickings.pdf

Foster, C. (2013). Non-linear inequalities. Mathematics in School, 42(3), 31–33. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Non-Linear%20Inequalities.pdf

Foster, C. (2013). Precise perimeters. Teach Secondary, 2(3), 30–32. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Precise%20Perimeters.pdf

Foster, C. (2013). A 3-sided story. Teach Secondary, 2(2), 32–34. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20A%203-Sided%20Story.pdf

Foster, C. (2013). Unequal reasoning. Mathematics in School, 42(1), 19–21. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Unequal%20Reasoning.pdf

Foster, C. (2013). Treat creationism as a misconception. Science Education Review, 11(3), 54–55. https://www.foster77.co.uk/Foster,%20Science%20Education%20Review,%20Treat%20Creationism%20as%20a%20Misconception.pdf

Back, J., Foster, C., Tomalin, J., Mason, J., Swan, M., & Watson, A. (2013). Tasks and their place in mathematics teaching and learning – part 2. Mathematics Teaching, 232, 6–8. https://www.foster77.co.uk/ATM-MT232-06-08.pdf

Foster, C. (2013). Connected quadratics. Teach Secondary, 2(1), 46–48. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Connected%20Quadratics.pdf

Foster, C. (2012). Connected expressions. Mathematics in School, 41(5), 32–33. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Connected%20Expressions.pdf

Foster, C. (2012). Straight to the point. Learning and Teaching Mathematics, 13, 6–10. https://www.foster77.co.uk/Foster,%20Learning%20and%20Teaching%20Mathematics,%20Straight%20to%20the%20Point.pdf

Foster, C. (2012). Shape up. Teach Secondary, 1(5), 24–26. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Shape%20Up.pdf

Back, J., Foster, C., Tomalin, J., Mason, J., Swan, M., & Watson, A. (2012). Tasks and their place in mathematics teaching and learning – part 1. Mathematics Teaching, 231, 33–37. https://www.foster77.co.uk/ATM-MT231-33-37.pdf

Foster, C. (2012). The what factor? Teach Secondary, 1(4), 56–58. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20The%20What%20Factor.pdf

Foster, C. (2012). Triangular roots. Mathematical Spectrum, 45(1), 8–9. https://www.foster77.co.uk/Foster,%20Mathematical%20Spectrum,%20Triangular%20Roots.pdf

Foster, C. (2012). What’s the point? Teach Secondary, 1(3), 39–41. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20What's%20The%20Point.pdf

Foster, C. (2012). Questions pupils ask: a straight question. Mathematics in School, 41(4), 31–34. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20A%20Straight%20Question.pdf

Foster, C. (2012). Parking problem. Mathematics Teaching, 229, 47–48. https://www.foster77.co.uk/ATM-MT229-47-48.pdf

Foster, C. (2012). Changing the subject. Teach Secondary, 1(2), 33–35. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20Changing%20the%20Subject.pdf

Foster, C. (2012). HCF and LCM – Beyond procedures. Mathematics in School, 41(3), 30–32. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20HCF%20and%20LCM%20-%20Beyond%20Procedures.pdf

Foster, C. (2012). Trigonometry without right angles. Mathematical Spectrum, 44(3), 98–101. https://www.foster77.co.uk/Foster,%20Mathematical%20Spectrum,%20Trigonometry%20Without%20Right%20Angles.pdf

Foster, C. (2012). Odd and even fractions. Mathematical Spectrum, 44(2), 69–72. https://www.foster77.co.uk/Foster,%20Mathematical%20Spectrum,%20Odd%20and%20Even%20Fractions.pdf

Foster, C. (2012). A day at the c-side: Introducing Pythagoras’ theorem. Teach Secondary, 1(1), 30–33. https://www.foster77.co.uk/Foster,%20Teach%20Secondary,%20A%20Day%20at%20the%20C-Side.pdf

Foster, C. (2012). Plus–minus graphs. Mathematics in School, 41(2), 32–33. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Plus-Minus%20Graphs.pdf

Foster, C. (2011). Sandbox: Rooting for you. Math Horizons, 19(2), 30. https://doi.org/10.4169/mathhorizons.19.2.30 pdf

Foster, C. (2011). A picture is worth a thousand exercises. Mathematics Teaching, 224, 10–11. https://www.foster77.co.uk/ATM-MT224-10-11.pdf (Extra material)

Foster, C. (2011). Straight dice. Symmetry Plus, 45(2), 9–10. https://www.foster77.co.uk/Foster,%20Symmetry%20Plus,%20Straight%20Dice.pdf

Foster, C. (2011). Small is beautiful after all. Mathematics Teaching, 222, 38–39. https://www.foster77.co.uk/ATM-MT222-38-39.pdf

Foster, C. (2011). Marking time. Mathematics Teaching, 222, 3–6. https://www.foster77.co.uk/ATM-MT222-03-06.pdf

Foster, C. (2011). Clock problem: 469. The New York State Mathematics Teachers’ Journal, 61(2), 92. https://www.foster77.co.uk/Foster,%20New%20York%20State%20Mathematics%20Teachers'%20Journal,%20Clock%20Problem.pdf

Foster, C. (2011). Table settings. Symmetry Plus, 44(1), 6–7. https://www.foster77.co.uk/Foster,%20Symmetry%20Plus,%20Table%20Settings.pdf

Foster, C. (2011). Questions pupils ask: odd questions pupils ask. Mathematics in School, 40(1), 34–35. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Odd%20Questions%20Pupils%20Ask.pdf

Foster, C. (2010). A formula for a square root. Mathematics Teaching, 220, 6. https://www.foster77.co.uk/ATM-MT220-06-06.pdf

Foster, C. (2009, March 12). Consistency – it’s a foolish obsession. SecEd, p. 6. https://www.foster77.co.uk/Foster,%20SecEd,%20Consistency%20-%20It's%20A%20Foolish%20Obsession.pdf

Foster, C. (2009). Reflections on editing MT 2005–2008. Mathematics Teaching, 212, 3. https://www.foster77.co.uk/ATM-MT-212-03-03.pdf

Foster, C. (2008). Connected codes. Journal of Recreational Mathematics, 37(2), 119–121. https://www.foster77.co.uk/Foster,%20Journal%20of%20Recreational%20Mathematics,%20Connected%20Codes.pdf

Foster, C. (2008, November 28). String along. Times Educational Supplement – Magazine, p. 30. https://www.foster77.co.uk/Foster,%20TES,%20String%20Along.pdf

Foster, C. (2008, November 21). Dead good. Times Educational Supplement – Magazine, p. 30. https://www.foster77.co.uk/Foster,%20TES,%20Dead%20Good.pdf

Foster, C. (2008, November 7). Add some fun. Times Educational Supplement – Magazine, p. 31. https://www.foster77.co.uk/Foster,%20TES,%20Add%20Some%20Fun.pdf

Foster, C. (2008). Questions pupils ask: how many detentions will I get? Mathematics in School, 37(5), 26–27. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20How%20Many%20Detentions%20Will%20I%20Get.pdf

Foster, C. (2008, October 31). Anyone for consistency? Times Educational Supplement – Magazine, p. 62. https://www.foster77.co.uk/Foster,%20TES,%20Anyone%20For%20Consistency.pdf

Foster, C. (2008, October 24). Who is missing? Times Educational Supplement – Magazine, p. 36. https://www.foster77.co.uk/Foster,%20TES,%20Who%20Is%20Missing.pdf

Foster, C. (2008, September 26). Exam boards should stick to examining. Times Educational Supplement, p. 45. https://www.foster77.co.uk/Foster,%20TES,%20Exam%20Boards%20Should%20Stick%20To%20Examining.pdf

Foster, C. (2008, September 5). Ready to shake on it. Times Educational Supplement, p. 34. https://www.foster77.co.uk/Foster,%20TES,%20Ready%20To%20Shake%20On%20It.pdf

Foster, C. (2008, August 8). Element of surprise keeps learning alive. Times Educational Supplement, p. 21. https://www.foster77.co.uk/Foster,%20TES,%20Element%20Of%20Surprise%20Keeps%20Learning%20Alives.pdf

Foster, C. (2008, July 18). Touching story. Times Educational Supplement – Magazine, p. 30. https://www.foster77.co.uk/Foster,%20TES,%20Touching%20Story.pdf

Foster, C. (2008). Making twelve. Journal of Recreational Mathematics, 37(1), 74. https://www.foster77.co.uk/Foster,%20Journal%20of%20Recreational%20Mathematics,%20Making%20Twelve.pdf

Foster, C. (2008, June 6). Name your price. Times Educational Supplement – Magazine, p. 34. https://www.foster77.co.uk/Foster,%20TES,%20Name%20Your%20Price.pdf

Foster, C. (2008, May 23). If the answer is instant, the question is pointless. Times Educational Supplement, p. 33. https://www.foster77.co.uk/Foster,%20TES,%20If%20The%20Answer%20Is%20Instant%20The%20Question%20Is%20Pointless.pdf

Foster, C. (2008). Higher priorities. Mathematics in School, 37(3), 17. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Higher%20Priorities.pdf

Foster, C. (2008). Leaping around. Mathematics Teaching, 208, 48. https://www.foster77.co.uk/ATM-MT208-48-48-mo.pdf

Foster, C. (2008, March 13). All my own work? SecEd, 7. https://doi.org/10.12968/sece.2008.3.1120 pdf

Foster, C. (2008, March 7). You’re having a graph. Times Educational Supplement – Magazine, pp. 58–59. https://www.foster77.co.uk/Foster,%20TES,%20You're%20Having%20A%20Graph.pdf

Foster, C. (2008, January 25). In the area. Times Educational Supplement – Magazine, p. 52. https://www.foster77.co.uk/Foster,%20TES,%20In%20The%20Area.pdf

Foster, C. (2008, January 18). Beware the rise of helicopter teachers. Times Educational Supplement, p. 29. https://www.foster77.co.uk/Foster,%20TES,%20Beware%20The%20Rise%20Of%20Helicopter%20Teachers.pdf

Foster, C. (2007). Twenty–one forever! Journal of Recreational Mathematics, 36(3), 194–195. https://www.foster77.co.uk/Foster,%20Journal%20of%20Recreational%20Mathematics,%20Twenty-One%20Forever.pdf

Foster, C. (2007, December 14). Counting cubes. Times Educational Supplement – Magazine, p. 45. https://www.foster77.co.uk/Foster,%20TES,%20Counting%20Cubes.pdf

Foster, C. (2007, November 8). Getting your bearings. SecEd, 12. https://doi.org/10.12968/sece.2007.5.902 pdf

Foster, C. (2007). Questions pupils ask: impossibility. Mathematics in School, 36(5), 13. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Impossibility.pdf

Foster, C. (2007, November 16). Solving the X factor. Times Educational Supplement – Magazine, pp. 48–49. https://www.foster77.co.uk/Foster,%20TES,%20Solving%20The%20X%20Factor.pdf

Foster, C. (2007, October 12). Stage fright does not equal lack of involvement. Times Educational Supplement, p. 29. https://www.foster77.co.uk/Foster,%20TES,%20Stage%20Fright%20Does%20Not%20Equal%20Lack%20Of%20Involvement.pdf

Foster, C. (2007, September 28). Pencils make a point. Times Educational Supplement – Magazine, pp. 48–49. https://www.foster77.co.uk/Foster,%20TES,%20Pencils%20Make%20A%20Point.pdf

Foster, C. (2007, September 21). Start making money. Times Educational Supplement – Magazine, p. 52. https://www.foster77.co.uk/Foster,%20TES,%20Start%20Making%20Money.pdf

Foster, C. (2007). The Warwick dials. Symmetry Plus, 34(3), 4. https://www.foster77.co.uk/Foster,%20Symmetry%20Plus,%20The%20Warwick%20Dials.pdf

Foster, C., & Williams, H. (2007). Mathematics is a spectator sport. Mathematics Teaching, 204, 40–41. https://www.foster77.co.uk/ATM-MT204-40-41-mo.pdf

Foster, C. (2007). Line multiplication. Mathematics Teaching, 203, 29. https://www.foster77.co.uk/ATM-MT203-29-29.pdf

Foster, C. (2007, May 24). Make maths sparkle. SecEd, 12. https://doi.org/10.12968/sece.2007.5.902 pdf

Foster, C. (2007, May 18). Pushing the limits. Times Educational Supplement – Magazine, p. 50. https://www.foster77.co.uk/Foster,%20TES,%20Pushing%20The%20Limits.pdf

Foster, C. (2007). A degree of confusion. Symmetry Plus, 33(2), 7. https://www.foster77.co.uk/Foster,%20Symmetry%20Plus,%20A%20Degree%20Of%20Confusion.pdf

Foster, C. (2007). Triangles and parabolas – The hard part! Symmetry Plus, 33(2), 3. https://www.foster77.co.uk/Foster,%20Symmetry%20Plus,%20Triangles%20And%20Parabolas%20-%20The%20Hard%20Part.pdf

Foster, C. (2007, May 11). Economies of scale. Times Educational Supplement – Magazine, p. 54. https://www.foster77.co.uk/Foster,%20TES,%20Economies%20Of%20Scale.pdf

Foster, C. (2007, May 11). There’s a positive side to negative marking. Times Educational Supplement, p. 27. https://www.foster77.co.uk/Foster,%20TES,%20There's%20A%20Positive%20Side%20To%20'Negative%20Marking'.pdf

Foster, C. (2007). Mathematical behaviour. Mathematics Teaching, 202, 12–13. https://www.foster77.co.uk/ATM-MT202-12-13-mo.pdf

Foster, C. (2007). As easy as 1, 2, 3, …? Mathematics Today, 43(2), 76. https://www.foster77.co.uk/Foster,%20Mathematics%20Today,%20As%20Easy%20As%201,%202,%203,%20....pdf

Foster, C. (2007, March 2). Petrol–pump learning won’t fuel thinking skills. Times Educational Supplement, p. 27. https://www.foster77.co.uk/Foster,%20TES,%20Petrol-Pump%20Learning%20Won't%20Fuel%20Thinking%20Skills.pdf

Foster, C. (2007). Right–angled triangles and parabolas. Symmetry Plus, 32(1), 10–11. https://www.foster77.co.uk/Foster,%20Symmetry%20Plus,%20Right-Angled%20Triangles%20And%20Parabolas.pdf

Foster, C. (2007). Stop interrupting! Equals, 13(1), 10–11. https://www.foster77.co.uk/Foster,%20Equals,%20Stop%20Interrupting.pdf

Foster, C. (2007). Questions pupils ask: introducing … Maths–man! Mathematics in School, 36(1), 15. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Introducing%20Maths-man.pdf

Foster, C. (2007, January 5). Model lessons put spontaneity in a straitjacket. Times Educational Supplement, p. 27. https://www.foster77.co.uk/Foster,%20TES,%20Model%20Lessons%20Put%20Spontaneity%20In%20A%20Straitjacket.pdf

Foster, C. (2006, November 24). To infinity and beyond. Times Educational Supplement – Magazine, p. 54. https://www.foster77.co.uk/Foster,%20TES,%20To%20Infinity%20And%20Beyond.pdf

Foster, C. (2006). A different pictorial way of looking at simultaneous equations. Mathematics in School, 35(5), 20–21. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20A%20Different%20Pictorial%20Way%20of%20Looking%20at%20Simultaneous%20Equations.pdf

Foster, C. (2006, November 17). Targets miss the point. Times Educational Supplement, p. 27. https://www.foster77.co.uk/Foster,%20TES,%20Targets%20Miss%20The%20Point.pdf

Foster, C. (2006). Emily’s discovery. Mathematics Teaching, 199, 30–31. https://www.foster77.co.uk/ATM-MT199-30-31-mo.pdf

Foster, C. (2006). Anamorphic art. Mathematics Teaching, 199, 24–25. https://www.foster77.co.uk/ATM-MT199-24-25-mo.pdf

Foster, C. (2006). Questions pupils ask: asking questions. Mathematics in School, 35(4), 24. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Asking%20Questions.pdf

Foster, C. (2006, September 14). Pointless compasses? SecEd, 13. https://doi.org/10.12968/sece.2006.9.705 pdf

Foster, C. (2006). ‘Wordsworth’ puzzle. Mathematics Teaching, 196, 48. https://www.foster77.co.uk/ATM-MT196-48-48-mo.pdf

Foster, C. (2006). Tessellations in Word. Mathematics Teaching, 196, 24–25. https://www.foster77.co.uk/ATM-MT196-24-25-mo.pdf

Foster, C. (2006). ‘2006’ puzzle. Mathematics Teaching, 195, 48. https://www.foster77.co.uk/ATM-MT195-48-48-mo.pdf

Foster, C. (2006). My accidental parabola. Mathematics Teaching, 195, 33. https://www.foster77.co.uk/ATM-MT195-33-33-mo.pdf

Foster, C. (2006, January 20). How do we get them going? Times Educational Supplement: Friday. https://www.foster77.co.uk/Foster,%20TES,%20How%20Do%20We%20Get%20Them%20Going.pdf

Foster, C. (2006). Preparing the lesson or preparing the teacher? Report: Association of Teachers and Lecturers, January, 11. https://www.foster77.co.uk/Foster,%20ATL%20Report,%20Preparing%20The%20Lesson%20Or%20Preparing%20The%20Teacher.pdf

Foster, C. (2006). Webwatch. Mathematics Teaching, 194, 47. https://www.foster77.co.uk/ATM-MT194-47-47-mo.pdf

Foster, C. (2006). Getting confused. Mathematics Teaching, 194, 18. https://www.foster77.co.uk/ATM-MT194-18-19-mo.pdf

Foster, C. (2005). Reflections. Mathematics Teaching, 192, 2. https://www.foster77.co.uk/ATM-MT192-02-02.pdf

Foster, C. (2005). What we did in our Easter holiday! Mathematics Today, 41(3), 71–72. https://www.foster77.co.uk/Foster,%20Mathematics%20Today,%20What%20We%20Did%20In%20Our%20Easter%20Holiday.pdf

Foster, C., Galligan, L., Mackrell, K., Mason, J., Melville, A., Piggott, J., & Watson, A. (2005). Freedom and constraint. Mathematics Teaching, 191, 37–39. https://www.foster77.co.uk/ATM-MT191-37-40.pdf

Foster, C. (2005). Another look at revision. Mathematics Teaching, 191, 6–7. https://www.foster77.co.uk/ATM-MT191-06-07.pdf

Foster, C. (2005). Slippery slopes. Mathematics in School, 34(3), 33–34. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Slippery%20Slopes.pdf

Foster, C. (2005). Golden opportunities for creativity. Mathematics Teaching, 190, 26–27. https://www.foster77.co.uk/ATM-MT190-26-27-mo.pdf

Foster, C. (2004). Differences over differences methods: Pros and cons of different ways of finding the \(n\)th term of a sequence of numbers. Mathematics in School, 33(5), 24–25. https://www.foster77.co.uk/Foster,%20Mathematics%20In%20School,%20Differences%20Over%20Differences%20Methods.pdf

Foster, C. (2004). Trapezium artist: Some thoughts on the formula for the area of a trapezium. Mathematics in School, 33(5), 6–7. https://www.foster77.co.uk/Foster,%20Mathematics%20in%20School,%20Trapezium%20Artist.pdf

Foster, C. (2004). Y8 area lesson. Mathematics Teaching, 188, 31. https://www.foster77.co.uk/ATM-MT188-30-31-mo.pdf

Foster, C. (2004). The \(n\)th term. Mathematics Teaching, 188, 30–31. https://www.foster77.co.uk/ATM-MT188-30-31-mo.pdf

Foster, C. (2003, March 14). Mean difference. Times Educational Supplement: Teacher, 5. https://www.foster77.co.uk/Foster,%20TES,%20Mean%20Difference.pdf

With thanks to the Association of Teachers of Mathematics and the Mathematical Association for permission to post the pdf versions of my articles above.

© Colin Foster 2026