# Lesson 4

Area of Rectangles

### Lesson Purpose

The purpose of this lesson is for students to continue to count squares to create rectangles and to find the area of rectangles with larger numbers than in the previous lesson.

### Lesson Narrative

In previous lessons, students identified equal groups in the rows and columns of arrays. In this lesson, students describe rectangles in terms of the rows and columns. They find the area of rectangles that have rows or columns of 2, 5, or 10 squares to encourage students to skip-count to find the total number of squares. Students should be encouraged to use the term “square units” in preparation for working with more specific units like square centimeters in future lessons. For example, if students find that a rectangle has 12 squares, they should say the area is 12 square units. In the next section, students formally relate area to multiplication.

• Representation
• MLR8

### Learning Goals

Teacher Facing

• Describe and represent the area of a rectangle as the total number of unit squares arranged in equal groups of rows and columns.
• Find the area of rectangles (within 60 square units) by counting unit squares.

### Student Facing

• Let’s find the area of more rectangles.

### Required Materials

Materials to Gather

### Required Preparation

Activity 1:

• Each group of 2 needs one folder.

### Lesson Timeline

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

### Teacher Reflection Questions

Reflect on your norms and routines. Are they promoting engagement from all of your students? Are there any adjustments you might make so that all students do math tomorrow?

### Suggested Centers

• Can You Build It? (3–5), Stage 1: Rectangles (Addressing)
• Five in a Row: Multiplication (3–5), Stage 1: Factors 1–5 and 10 (Supporting)