## Lesson: Distributive Property of Multiplication

Developing the Concept

In this lesson, students use the Distributive Property to multiply three-digit numbers by two-digit numbers.

**Materials:** none

**Preparation:** none

**Prerequisite Skills and Background:** Students should know basic multiplication and addition facts, how to expand numbers, and how to multiply three-digit numbers by one-digit numbers.

Write 45 x 123 in vertical form on the board.

Write a plus sign, an equals sign, and 5,400 to show the connection between the partial products and the final product.

On the board, write several multiplication exercises that have three-digit factors and two-digit factors. Invite volunteers to find the products. Have them explain how the Distributive Property was used.

**Wrap-Up and Assessment Hints**

Students require a lot of practice in multiplying three-digit numbers by two-digit numbers. Offer grid paper or use lined paper turned sideways to keep place values aligned correctly. Frequently revisit the Commutative, Associative, and Distributive Properties of Multiplication in order to reinforce their use in paper-and-pencil multiplication and in mental math. Display the properties, their names, and numerical examples around the room to aid students in their work.