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How to divide fractions

A short, no-nonsense walkthrough — the steps, the gotchas, and answers to the usual questions.

5 minutes Easy

Dividing fractions is done by flipping the second fraction and multiplying. Once you know this keep, change, flip method, division becomes as easy as multiplication.

Step by step

  1. Write the division problemSet up the two fractions with a division sign, for example 1/2 divided by 3/4.
  2. Keep the first fractionLeave the first fraction exactly as it is. In the example, 1/2 stays the same.
  3. Change division to multiplicationReplace the division sign with a multiplication sign.
  4. Flip the second fractionSwap the top and bottom of the second fraction to get its reciprocal. So 3/4 becomes 4/3.
  5. Multiply acrossMultiply the numerators and the denominators. Here 1 times 4 over 2 times 3 gives 4/6.
  6. Simplify the answerReduce the fraction to lowest terms. In the example, 4/6 simplifies to 2/3.

Handy tips

  • The reciprocal of a fraction is just that fraction turned upside down.
  • To divide by a whole number, write it over 1 first, so dividing by 5 means multiplying by 1/5.
  • Dividing by a fraction less than 1 gives an answer larger than the number you started with.

FAQ

Why do you flip the second fraction?

Dividing by a number is the same as multiplying by its reciprocal. Flipping the second fraction turns the division into an equivalent multiplication problem.

Do I flip the first fraction or the second?

Only the second fraction, the one you are dividing by. The first fraction stays unchanged.

How do I divide a fraction by a whole number?

Write the whole number as a fraction over 1, then flip it. For example, 3/4 divided by 2 becomes 3/4 times 1/2, which equals 3/8.