Lesson objective: Compare relationships with percents using double number lines.

This lesson helps to build fluency with using double number lines to reason with percents. Double number lines are used here because they support the development of multiplicative reasoning. This work develops students' understanding that percents allow us to compare relationships based on different totals by standardizing those comparisons to a value of 100.

Students engage in Mathematical Practice 1 (Make sense of problems and persevere in solving them) as they interpret the information that is given to them and make sense of the relationships between the values being described in the problems.

**Key vocabulary:**

- double number line
- percent
- ratio