Education Technology

# Activities

• ##### Subject Area

• Math: Algebra I: Linear Inequalities

9-12

45 Minutes

• ##### Device
• TI-Nspire™ CX/CX II
• TI-Nspire™ CX CAS/CX II CAS
• TI-Nspire™
• TI-Nspire™ CAS
• ##### Software

TI-Nspire™
TI-Nspire™ CAS

3.2

## Multiplying Inequalities by Negative Numbers

#### Activity Overview

Investigate the effect of multiplying the numbers on a number line by a negative number.

#### Objectives

• Students will relate the inequality symbol to the location of points on a number line.
• Students will recognize, moreover, that the value of a number depends on its position on the number line and that numbers farther to the left are smaller.
• Students will recognize what operations on an inequality reverse the direction of the inequality.

#### Vocabulary

• inequality statement

#### About the Lesson

In this lesson students investigate the effect of multiplying the numbers on a number line by a negative number and the symbolic and graphical representations of the solutions of an inequality. Students will change the value of a multiplier (k) and observe the effects on the position of the resulting number on the number line and in the inequality statements. As a result, students will recognize what operations on an inequality reverse the direction of the inequality.