### Lesson Summary

### Overview

In this CYBERCHASE activity, students are informally introduced to the idea of inverse operations as Bianca imagines herself as a spy. After infiltrating a fortress, she must do the inverse of her steps to escape. Students are asked to explain why she fails. In this context, students learn to describe the inverse of a sequence of operations in written form, and then they will solve two-step equations and check their solutions.

### Grade Level:

5-8

### Suggested Time

1 hour

### Media Resources

Bianca the Spy QuickTime Video

### Materials

Handout 1: Inverses

Assessment: Level A

Assessment: Level B

Answer Key

### The Lesson

### Part I: Learning Activity

1. Read the following to your students: "Bianca is so bored she has a fantasy of being a secret agent. In her imaginary adventure, she must enter a hidden fortress, find the video game eliminator, and replace the red crystal with a blue crystal. She follows the instructions successfully, and then she has to do the inverse of her instructions, and backtrack through her moves, to avoid setting off the alarms. Watch the video clip and see if you can figure out where and how she makes her mistake."

2. Play the Bianca the Spy QuickTime Video .

3. Discuss with the students where Bianca made her mistake in the spy adventure.

4. Distribute Handout 1: Inverses .

5. Ask students to complete the handout.

6. Discuss the handout with students.

### Part II: Assessment

Assessment: Level A (proficiency): Students solve two-step equations using inverse operations with positive integer coefficients.

Assessment: Level B (above proficiency): Students solve two-step equations using inverse operations with decimal and fractional coefficients.