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/cm3, it is the same in ml as 1 ounce is in grams.)
© Colin Foster 2012, www.foster77.co.uk