Lesson objective: Practice finding unit rates, and use unit rates to compare and write other ratios.

This lesson provides an opportunity for students to practice finding unit rates. Ratio tables are used here because they support the ability to scale up and down while keeping track of units. This work develops students' understanding that every ratio can be associated with a unit rate; the ratio a:b is associated with the unit rate a/b:1.

Students engage in Mathematical Practice 2 (Reason abstractly and quantitatively) as they use tables to scale ratios down to unit rates, and then scale back up to create other ratios. Students must keep careful track of the meaning of the quantitites and the units involved.

**Key vocabulary:**

- ratio table
- unit rate
- scale down / scale up