# Lesson 22

### Lesson Purpose

The purpose of this lesson is for students to apply what they know about multiplication and division to convert units of measurement and solve multi-step problems involving perimeter and area.

### Lesson Narrative

This lesson prompts students to apply their reasoning skills and knowledge of all operations to solve problems about area and perimeter. Along the way, students also use multiplication and division to convert units of measurement. Most numbers used here are two- and three-digit numbers. The problems in the lesson may include more than one step and can be solved in multiple ways, offering students opportunities to construct logical arguments to communicate their thinking and to critique the reasoning of others (MP3). As students begin the lesson remind them of their past experiences with multi-step problems and explain that the problems in this lesson may involve more than one step.

• Representation
• MLR8

Activity 1: Create a Class Banner

### Learning Goals

Teacher Facing

• Solve multi-step problems involving measurement conversions, perimeter, and area.

### Student Facing

• Let’s solve situations involving perimeter and area.

### Required Materials

Materials to Gather

### Lesson Timeline

 Warm-up 10 min Activity 1 15 min Activity 2 20 min Lesson Synthesis 10 min Cool-down 5 min

### Teacher Reflection Questions

Some problems in the lesson can reveal the depth of students’ understanding of multiplication and division, the flexibility of their thinking, and their ability to make use of structure. What evidence of flexible reasoning, structural thinking, or deep understanding did you see today?

### Suggested Centers

• Compare (1–5), Stage 7: Multi-digit Operations (Addressing)