Lesson objective: Write and solve equations to represent percent increase situations.

This lesson helps with understanding percent change by writing and solving equations. Double number lines and ratio equations are used here as both help students understand the connection between the values in a ratio and the percent change. This work develops students' understanding that equations can be set up in different ways to solve percent problems.

Students engage in Mathematical Practice 2: Students will reason abstractly and quantitatively as they write and solve algebraic equations to represent real life problems involving percent.

**Key vocabulary:**

- double number line
- original value
- percent change
- percent decrease
- percent increase
- ratio equation

**Special materials needed:**