Videos and solutions to help Grade 3 students learn how to form rectangles by tiling with unit squares to make arrays.

Common Core Standards: 3.MD.5, 3.MD.6, 3.MD.7a, 3.MD.7b, 3.MD.7d

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Lesson Plans and Worksheets for Grade 3

Lesson Plans and Worksheets for all Grades

More Lessons for Grade 3

Common Core For Grade 3

New York State Common Core Math Module 4, Grade 3, Lesson 5

Application Problem

Candice uses square-centimeter tiles to find the side lengths of a rectangle as shown. She says the side lengths are 5 centimeters and 7 centimeters. Her partner, Luis uses a ruler to check Candice’s work and says that the side lengths are 5 centimeters and 6 centimeters. Who is right? How do you know?

Note: This problem reviews G3–M4–Lesson 4, specifically the relationship between the number of tiles and the side length.

Concept Development

Concrete: Understand the relationship between side lengths and area.

Concrete/Pictorial: Form rectangles and determine area or side lengths by drawing to make arrays.

1. Use the centimeter side of a ruler to draw in the tiles, then skip-count to find the unknown side length or area. Write a multiplication sentence for each tiled rectangle.

2. Ally makes a rectangle with 45 square-inch tiles. She arranges the tiles in 5 equal rows. How many square-inch tiles are in each row? Use words, pictures, and numbers to support your answer.

3. Leon makes a rectangle with 36 square-centimeter tiles. There are 4 equal rows of tiles.

a. How many tiles are in each row? Use words, pictures, and numbers to support your answer.

b. Can Leon arrange all of his 36 square-centimeter tiles into 6 equal rows? Use words, pictures, and numbers to support your answer.

c. Do the rectangles in (a) and (b) have the same total area? Explain how you know.

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