Area Matters! Finding the Area of Rectangles

Contributor: Victoria Surface. Lesson ID: 10008

How does a painter know how much paint to buy? Or a gardener how much dirt he needs? How do you figure these things out without wasting money? Learn how to find area and design your own playground!

categories

Measurement and Data, Plane Geometry (2D)

subject
Math
learning style
Kinesthetic, Visual
personality style
Lion
Grade Level
Intermediate (3-5)
Lesson Type
Dig Deeper

Lesson Plan - Get It!

Audio:
  • Have you ever wondered how a painter knows how much paint to buy?
  • Or how a gardener knows how much dirt to buy?
  • Or how much mulch it takes to cover a playground?
  • How do people figure these things out without wasting money or running out?

In this lesson, you will learn about finding the area of a rectangle using multiplication, and even design your very own playground!

Let's learn how we can use multiplication to find the area of a rectangle.

Watch the videos below to learn what area is and how to find the area of a rectangle. Answer the following questions as you work through the videos:

  • What is the definition of area?
  • How can you find the area of a rectangle?
  • Is there more than one way to find the area of a rectangle?
  • How should the area of a rectangle always be labeled?

Learn how to calculate the area of a rectangle in What is Area?, from Miller Math:

Now learn how to calculate the area of a rectangle in Learn Area - 3rd Grade Math Video, from Math & Learning Videos 4 Kids:

After watching the videos, answer the following question in a paragraph:

  • How do you find the area of a rectangle using the formula area equals length times width?

Give step-by-step instructions for finding the area of a rectangle. Use the Graphic Organizer - Flow Chart in Downloadable Resources in the right-hand sidebar to organize your thoughts.

Try it this way: Pretend you are teaching a younger person how to find the area of a rectangle by multiplying. Give specific instructions, such as: First you do this, then you do this, etc.


To learn how to multiply 2-digit by 2-digit numbers or just review the process, watch the following two videos:

How to solve 2-digit by 2-digit multiplication~Revised from Ms. Greenlee:

Multiplication Box Method Strategy from TeacherTube Math:


Now, practice finding the area of a rectangle (or square) in a word problem. The following is an example of a word problem:

basketball court

A rectangular basketball court is 29 meters long by 15 meters wide. What is the area of the basketball court?

For more practice before moving on, create the same shape as the basketball court using your LEGO®s. Make a rectangle using 435 posts (the little round things that stick up and go into the holes of the other blocks).

Now, try some of these:

  • Make a rectangle using 120 posts.
  • Make a rectangle using 350 posts.
  • Make a rectangle using 95 posts.

Continue on to the Got It? section to work on some every-day problems!

Elephango's Philosophy

We help prepare learners for a future that cannot yet be defined. They must be ready for change, willing to learn and able to think critically. Elephango is designed to create lifelong learners who are ready for that rapidly changing future.