Lesson 10

Multiply!

Lesson Narrative

The purpose of this optional lesson is to provide students with practice multiplying rational numbers. Students see products of three numbers, and figure out what to do with a product of three negative numbers by grouping two of them together and multiplying those first. They see products involving unit fractions, reminding them that dividing by a whole number is the same as multiplying by its reciprocal. This will be useful in the next lesson when they start to divide rational numbers.

Learning Goals

Teacher Facing

  • Identify multiplication expressions that are equal, and justify (orally) that they are equal.
  • Multiply rational numbers, including multiplication expressions with three factors, and explain (orally and in writing) the reasoning.

Student Facing

Let’s get more practice multiplying signed numbers.

Required Preparation

For the Card Sort: Matching Expressions activity, prepare 1 copy of the blackline master for each group of 2 students. If possible, copy each complete set on a different color of paper, so that a stray card can quickly be put back.

Learning Targets

Student Facing

  • I can solve problems that involve multiplying rational numbers.

CCSS Standards

Building On

Addressing

Building Towards