# Lesson 14

Percent Increase and Decrease

These materials, when encountered before Algebra 1, Unit 5, Lesson 14 support success in that lesson.

### Lesson Narrative

In this lesson, students get practice writing expressions for percent increase or decrease using only multiplication. They explore tape diagrams and rewriting equivalent expressions using the distributive property to develop skills to write percent change expression. A repeated percent increase or decrease is an exponential change. Knowing how to express percent change using multiplication only will help students represent exponential change in upcoming Algebra 1 lessons involving compound interest and population changes. When students recognize that the distributive property can be used to rewrite an expression, they are noticing and making use of structure (MP7).

### Learning Goals

Teacher Facing

• Write expressions using only multiplication to represent a percent increase or decrease.

### Student Facing

• Let’s express increasing or decreasing by a percentage using only multiplication.