# Lesson 3

Tile Rectangles

### Lesson Purpose

The purpose of this lesson is for students to measure area by counting square tiles and create rectangles with a given area.

### Lesson Narrative

In previous lessons, students learned that counting square tiles that cover a figure gives the area of the figure in square units. In this lesson, students further explore tiling and learn that, when measuring area, squares that are used to tile a figure can't overlap. They learn that the area is the number of square units that cover a flat figure with no gaps or overlaps. Students also create rectangles of a specific area on grids to demonstrate they understand that rectangles covered by the same number of square units without gaps or overlaps have the same area.

Students should have access to square tiles throughout the lesson and also be encouraged to draw the partitioned rectangles they create with the tiles.

• Representation
• MLR8

### Learning Goals

Teacher Facing

• Explain that rectangles that can be covered by the same number of unit squares without gaps or overlaps have the same area.
• Find the area of rectangles (within 24 square units) by counting unit squares.

### Student Facing

• Let’s count square tiles.

### Required Materials

Materials to Gather

Materials to Copy

• Card Sort: Rectangles
• Time to Tile

### Required Preparation

Activity 1:

• Each group of 2 needs 24 square tiles.

Activity 2:

• Create a set of cards from the blackline master for each group of 2.

### 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

Reflect on students’ counting strategies. What strategies are they comfortable using as they find area? What strategies could use more practice?

### 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)

### Print Formatted Materials

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