# Algebraic Expressions Lesson 1 (Teachers)

### Using Algebra to Express a Generalization (Method 1)

Haleemah and ET create a method for finding the number of tiles in the border of a swimming pool. Then they apply their method to pools of different sizes and generalize their method. Finally, they write an algebraic equation to express their generalization and explain what each part of the equation means in the pool context.

##### Episode 1: Making Sense

ET and Haleemah make sense of a swimming pool context and create a method for finding the number of tiles in the border of the pool.

##### Episode 2: Repeating Your Reasoning

The students apply their method for finding the number of tiles in the border to swimming pools of different sizes.

##### Episode 3: Exploring

Haleemah and ET generalize their method and write an algebraic equation that shows the relationship between a border with any number of tiles on one side and the total number of tiles in the border.

##### Episode 4: Reflecting

The students work to explain what each symbol in their equation means in the pool context and encounter a challenge.

##### Episode 5: Reflecting

ET and Haleemah resolve a struggle from the previous episode and connect each part of their algebraic equation to its meaning in the swimming pool context.

### Mathematics in this Lesson Targeted Understandings

This lesson can help students:

Common Core Math Standards

Common Core Math Practices