Find Area - Associative Property

Videos to help Grade 3 students learn how to demonstrate possible whole number side lengths of rectangles with areas of 24, 36, 48, or 72 square units using the associative property.

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

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Common Core For Grade 3

New York State Common Core Math Module 4, Grade 3, Lesson 11

Application Problem

The restaurant’s banquet table measures 3 feet by 6 feet. For a large party, workers at the restaurant place 2 banquet tables side by side to create 1 long table. Find the area of the new, longer table.

Note: This problem reviews G3–M4–Lesson 10’s concept of applying the distributive property to find the total area of a large rectangle by adding two products. It also reviews factors of 36 and multiples of 12 that lead into the Concept Development.

Concept Development

Find different side lengths for rectangles that have area of 36 square units.
Repeat the process with rectangles that have areas of 24, 48, and 72 square units.

Lesson 11 Homework

1. The rectangles below have the same area. Move the ( ) to find the missing side lengths. Then solve.

3.a. Find the area of the rectangle below.
b. Hilda says a 4 cm by 12 cm rectangle has the same area as the rectangle in Part (a). Place ( ) in the equation to find the related fact and solve. Is Hilda correct? Why or why not?