Does the inverse relationship between multiplication and division stay the same when multiplying and dividing

fractions?

In this lesson you will learn how to check your answers when dividing fractions by thinking about the inverse

relationship between multiplication and division.

Let’s ReviewLet’s Review

4 x 6 = 246 x 4 = 2424 _ 6 = 424 _ 4 = 6

Fact Families are a collection of related facts.

4 6

24

Let’s ReviewLet’s Review 35 _ 7 = 5How can I

check to see if my answer is

correct?

So…35 divided into 7

equal groups results in 5 per group.

I know that seven groups of five is 35…

Let’s ReviewA Common Mistake

A common mistake is to forget that the inverse relationship of multiplication and

division remains the same, no matter what kind of numbers you are working with.

2 _ = 3

2 _ 3 =

3 x = 2

x 3 = 2

Let’s ReviewCore Lesson

_ = ?

1 whole

1 whole

14

14

14

14

18

18

18

18

1818

18

18

14

14

14

3

18

18

281

18

18

28

18

18

282 3

Does this answer

make sense?

Let’s ReviewCore Lesson

1 whole18

18

28

18

18

28

18

18

28

14

14

14

14

14

14

14

34

x =

This answer makes sense!

_ =

Let’s ReviewCore Lesson

_ = ?

12

12

18

18

18

18

1818

18

18

1818181818

One set of …

45

11 2 3 4 This answer makes sense because it is less than 1.

My answer should be less

than 1.

Let’s ReviewCore Lesson

x =

=

_ =

x =

In this lesson you have learned how to check your answers when dividing fractions by thinking about the inverse

relationship between multiplication and division.

Let’s ReviewGuided Practice

_ =

Let’s ReviewGuided Practice

_ =

Let’s ReviewExtension Activities

Charlie solved these three division problems. Please check his work by using related multiplication facts. Are his answers correct?

_ =

_ =

2 _ =

Let’s ReviewExtension Activities

Use a deck of cards (1 – 10 only) to create division problems. If you happen to create an improper fraction (numerator greater than denominator), you may switch the order of the cards or change it to a mixed number if you wish.

Now SOLVE. (If necessary, use fraction bars to build and solve the problems.)

Place four cards as shown.

_CARD CARD

CARD CARD

Be sure to check your answers by using multiplication!

Let’s ReviewQuick Quiz

Solve each problem. Use multiplication to check your answers.

_ = ?

1 _ = ?