Proportions  Rates, Ratios, and Proportions
Proportions
Everyone has somehow seen and used proportions before, such as baking recipes and maps. Proportion is basically another way to say two ratios or rates are equal. We can represent proportions in two ways: in the form of fraction (a/b = c/d) and using a colon (a:b = c:d).
Basic concepts:
 Ratios
Lessons

2.
Find the missing value.