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

Elementary

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 video below from Kisi KidsMathTV to learn how to find the area of a rectangle. Answer the following questions as you work through the video:

  • What is the definition of area?

  • What are two ways to find the area of a rectangle? Which way do you think is more efficient or faster?

  • How should the area of a rectangle always be labeled?

Learn how to calculate the area of a square and rectangle. Math lesson for kids:

 

Explore more about finding the area of a rectangle by watching the following Rectangle area as product of dimensions same as counting unit squares video from Khan Academy. After watching the video, answer the following question in a paragraph (see below): How do you find the area of a rectangle using multiplication?

 

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.

Next, practice finding the area of a rectangle using Transition from unit squares to area formula from Khan Academy.

Continue to practice finding the area of a rectangle (and some squares, too!) with more challenging problems. Remember, finding the area of a square is the same as finding the area of a rectangle. The square will always have sides that are the same length.

Visit the following link for more practice: Area of squares and rectangles from IXL Learning, Inc.


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:

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

Picture

Multiplication

Multiplication Box Method

29m

 
 

15 m

   

2

9

 

X

1

5

 

1

4

5

+

2

9

0

 

4

3

5

 

20

9

 

2

0

0

10

200

90

 

1

0

0

5

100

45

   

9

0

       

+

4

5

       

4

3

5

 

Visit the following link for area word problems: Area of squares and rectangles: word problems from IXL Learning, Inc.

You may find it helpful to draw out the rectangle so you can visualize the problem.

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!

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