How can we use the Commutative and Associative

Properties to transform the expression 25 x (-16 x -4) into

(25 x -4) x -16?

In this lesson you will learn to solve multiplication problems

by using the Commutative and Associative Properties.

Let’s Review

If a, b and c are rational numbers then a x (b x c) = (a x b) x c

Associative Property of Multiplication

Let’s Review

If a and b are rational numbers then a x b = b x a

Commutative Property of Multiplication

A Common Mistake

25 x (-16 x -4) = (25 x -4) x -16

Core Lesson

Multiply inside the parentheses

Multiply

Core Lesson

Apply Associative Property

Multiply inside the parenthesesMultiply

Apply Commutative

Property

Core Lesson

Multiply

Multiply first two numbers

Core Lesson

Apply Associative Property

Apply Associative Property

Apply Commutative Property

Core Lesson

Multiply inside the parentheses

Multiply

Multiply

Core Lesson

Multiply inside the parentheses

Multiply

Core Lesson

Apply Associative Property

Multiply what’s in the parentheses

Multiply

Apply Commutative

Property

Core Lesson

Multiply

Multiply inside the parentheses

Core Lesson

Apply Associative Property

Multiply inside the parentheses

Multiply

Apply Commutative

Property

In this lesson you have learned to solve multiplication problems by using the

Commutative and Associative Properties.

Guided Practice

1. Using the Commutative and Associative Properties, solve the following problem:

Guided Practice

2. Using the Commutative and Associative Properties, solve the following problem:

Extension Activities

1. Show each step and name the properties that transform 19 x -4 x 5 to 5 x -4 x 19.

Extension Activities

2. Use the commutative and associative properties to transform a x b x x d into d x c x b x a.

Quick Quiz

1. Using the associative property, solve the following problem:

2. Using the associative property, solve the following problem: