OML Search

Use Side Lengths to find Area


Videos to help Grade 3 students learn how to find the area of a rectangle through multiplication of the side lengths.

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

Related Topics:
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 8

Application Problem

Marnie and Connor both skip-count square units to find the area of the same rectangle. Marnie counts, “3, 6, 9, 12, 15, 18, 21.” Connor counts, “7, 14, 21.” Draw what the rectangle might look like, then label the side lengths and find the area.

Note: This problem reinforces G3–M4–Lesson 7 and sets the foundation for today’s Concept Development. Invite students to share their drawings and discuss how they are similar and how they are different.

Concept Development

Part 1: Relate side lengths to area.

Part 2: Use side lengths to find area.

Part 3: Use area and side length to find unknown side length.

Lesson 8 Homework

1. Write a multiplication sentence to find the area of each rectangle.

2. Write a multiplication sentence and a division sentence to find the unknown side length for each rectangle.

2. On the grid below draw a rectangle that has an area of 32 square centimeters. Label the side lengths.

4. Charles draws a rectangle with a side length of 9 inches and an area of 27 square inches. What is the other side length? How do you know?

Rotate to landscape screen format on a mobile phone or small tablet to use the Mathway widget, a free math problem solver that answers your questions with step-by-step explanations.

You can use the free Mathway calculator and problem solver below to practice Algebra or other math topics. Try the given examples, or type in your own problem and check your answer with the step-by-step explanations.

OML Search

We welcome your feedback, comments and questions about this site or page. Please submit your feedback or enquiries via our Feedback page.

[?] Subscribe To This Site

follow us in feedly
Add to My Yahoo!
Add to My MSN
Subscribe with Bloglines