7.RP.A.2.b: Identify the constant of proportionality (unit rate) in tables, graphs, equations, diagrams, and verbal descriptions of proportional relationships.
Students will learn how to identify unit rates in tables (video), graphs (video), equations (video), and word problems (video). Students should be shown two ways of identifying unit rates in tables. The first way is to plot the points, finding the unit rate graphically. The second way is to find the unit rate by arithmetic.
Concude by giving your students this challenge:
Three Spinners by NRICH
Here's the solution: Start by writing down the numbers for each spinner. We know 7 of the red numbers, 8 of the blue, and 8 of the yellow. Look at the first set of unknown numbers. 3, 5, 7, 9 are not red numbers. But we know 7 of the red numbers. Thus, the first set of unknown numbers can't be red. Similarly, 5, 7, 9, are not yellow numbers. But we know 8 of the yellow numbers. Thus, the first set of unknown numbers can't be yellow either. Thus, they must be blue. The solution continues in this way.