Dividing Fractions Review

Lesson Plan - Get It!

Audio:

When you divide whole numbers, such as 15 divided by 5, you are asking,"How many 5s are in 15?"

If you divide fractions, such as ½ ÷ ¼, you are asking, "How many ¼s are in ½?"

As you watch Math Antics - Dividing Fractions to review multiplying fractions, write down the answers to these questions:

• What is a reciprocal?
• How is a reciprocal important to dividing fractions?
• What is the procedure for dividing fractions?

When you divide fractions, you are actually turning the problem into multiplication!

Dividing is the opposite of multiplying, but multiplying fractions is easier, so it is easier to change a problem to multiplication.

There are a few ways to help you remember the steps for dividing fractions.

All of the following phrases and rhymes work for dividing fractions, so pick one that you like best to help you with dividing fractions!

Remember the phrase, "Keep, Change, Flip."

• Keep the first fraction the way it is.
• Change the division sign to multiplication.
• Flip the second fraction so it becomes a reciprocal.

Remember the phrase, "Leave me, Change me, Turn me over."

• Leave the first fraction.
• Change the symbol.
• Turn the second fraction over.

Read and remember this rhyme:

• "Dividing fractions, as easy as pie,
  Flip the second fraction, then multiply.
  And don't forget to simplify,
  Before it's time to say goodbye."

Follow these four steps to divide fractions:

1. Take the reciprocal of the second fraction.
2. Rewrite the problem by keeping the first fraction the same; change the division symbol to multiplication; then write the reciprocal.
3. Multiply the numerators and denominators straight across.
4. Simplify the fraction.

Now, solve the question from the beginning of the lesson:

You bought a ¹⁄₂-pound bag of candy at the store for your party. Each gift bag needs ¹⁄₈ pound of candy.

How many ¹⁄₈-pound gift bags can you make?

• Can you draw a model to help you solve this problem?

Think about the following:

• Which method do you like best to help you remember how to divide fractions?

Write down or repeat the phrase or rhyme.

Now, move on to the Got It? section to practice dividing fractions with an interactive game and practice.