Guide

How to Multiply Fractions

Multiplying fractions is the simplest of the four operations — no common denominator needed.

Unlike adding and subtracting, multiplying fractions needs no common denominator. You simply multiply straight across.

Step by step

1
Multiply the numerators
Multiply the two top numbers. For 2/3 x 3/4, that's 2 x 3 = 6.
2
Multiply the denominators
Multiply the two bottom numbers: 3 x 4 = 12.
3
Write the new fraction
Put the results together: 6/12.
4
Simplify
Reduce to lowest terms: 6/12 = 1/2.

Multiply 2/3 x 3/4. Multiply tops: 2 x 3 = 6. Multiply bottoms: 3 x 4 = 12. That gives 6/12, which simplifies to 1/2.

Trying to find a common denominator first (you don't need one to multiply).
Forgetting to simplify.
Multiplying a fraction by a whole number without writing the whole number as a fraction over 1.

Try it yourself on the Multiply Fractions Calculator, generate a printable worksheet, or work through it one step at a time in guided practice.

Do you need a common denominator to multiply fractions?

No. You multiply the numerators together and the denominators together, then simplify.

How do you multiply a fraction by a whole number?

Write the whole number as a fraction over 1, then multiply straight across. For example 5 x 1/3 = 5/1 x 1/3 = 5/3.

What does 'of' mean in fraction problems?

In math, 'of' usually means multiply. '1/2 of 3/4' means 1/2 x 3/4.