Lesson 20 The Commutative Property

    • Let’s learn about the commutative property.

Warm-up Number Talk: Subtraction

Find the value of each expression mentally.

Activity 1 Learn More About Multiplication

Image A

Array. 2 groups of 5.

Image B

Array. 5 groups of 2.

Problem 1

What do you notice? What do you wonder?

Problem 2

  1. Write an array situation for each array.

  2. How are the situations the same? How are the situations different?

Problem 3

  1. Write an equation for each situation.

  2. How does your equation connect to the situation and array?

Activity 2 Revisit Arrays

An array.

  1. Write 2 multiplication equations that represent the array.

  2. Explain why both equations can represent the array.

Practice Problem

Problem 1

  1. Write a multiplication equation that represents each array.

    1
    an array.
    2
    an array.

  2. How are the arrays the same? How are they different?