**possible
related topics** converting units, ratio

Learners could create a graph with volume on the horizontal axis and the costs of the different drinks on the vertical axis.

They will need to know that 1 fluid ounce (fl oz) = 28 ml.
(A fluid ounce is the volume of 1 ounce of water and, since water has a density
of 1 g/cm^{3}, it is the same in ml as 1 ounce is in grams.)

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© Colin Foster 2012, www.foster77.co.uk