Lesson 10 Solve Area Problems

    • Let’s solve area problems.

Warm-up Number Talk: One More Group

Find the value of each expression mentally.

Activity 1 Paint a Wall

Picture of small, medium, and large paint containers.

Noah is painting a wall in a community garden. The wall is shaped like a rectangle. A diagram of the wall is shown here.

Rectangle. Horizontal side, 6 meters. Vertical side, 3 meters.

Paint is sold in 3 different sizes:

  • A small container will cover 3 square meters.

  • A medium container will cover 10 square meters.

  • A large container will cover 40 square meters.

What should Noah buy? Explain your reasoning.

Activity 2 Create a Garden

Raised garden bed.

Problem 1

Elena is planning how to use her rectangular space in the community garden. She needs a space that is at least 20 square feet to fit her plants. She has enough soil for a garden that is 30 square feet. The space she has available has to be 3 feet on one side.

What are the possible sizes for her garden?

Create a poster to show your thinking. Organize it so it can be followed by others.

Problem 2

As you look at the posters with your group:

  1. Describe how another group solved the problem in a different way than your group did.

  2. Write three things you saw that helped you understand how other students solved the problem.

Practice Problem

Problem 1

Tyler has 40 carpet squares that are 1 foot on each side. He wants to use all of them to make a rectangle-shaped carpet for his room.

For the carpet to fit in the room, the longest side cannot be more than 12 feet. What side lengths could Tyler’s rectangle have?