How can we use area models to find all the factor pairs of a number?

For example:Find all the factors pairs of 20.

In this lesson you will learn how to find all the factor pairs

of a number by using area models.

Let’s ReviewMultiplication can be shown

as an area model, also known as a rectangular array.

= 6x

2

3

Let’s Review

=x

2

3x

3

2

Let’s Review

FactorFactor

1x6=6

61

Factors

A Common Mistake

When listing factor pairs, don’t forget to list the number as a factor of itself.

6= 1x6

Core Lesson

6: 1 x6

61

2

3

Find all the factor pairs for 6.

2 x3

Core LessonFind all the factor pairs for 20.

20: 1 x 20

120

210

4

5 2 x 104 x 5

In this lesson you have learned how to find all the factor pairs of a number by using an area

model.

Guided Practice

Find the factor pairs for 18.

118

29

3

618: 1 x 18

2 x 93 x 6

Extension Activities

Find the factor pairs for 15.

Find the factor pairs for 30.

What factors do they have in common? Why?

Extension Activities

Find all the factor pairs for 35.

Extension ActivitiesGAME: Factor Capture

Materials: (1) Set of playing cards with the Kings, Queens, & Jacks removed.(2) Paper and pencil for each playerDirections: Place all the cards in a stack between the players. Flip over two cards and multiply the two cards by each other. Players have one minute to list as many factor pairs as they can for that product. When one minute is over, the student with the most correct factor pairs wins and places the cards in a ‘win stack’. If no one wins, leave the cards for the next round.

Quick Quiz

Find the factor pairs for 42.

Find the factor pairs for 28.