How to Multiply Fractions With Common Denominators

By C. Taylor; Updated April 24, 2017
Multiplying fractions requires separately multiplying the numerators and then the denominators.

Multiplying fractions is essentially taking a fraction of a fraction. As an example, multiplying 1/2 times 1/2 is the same as taking a half of a half, which you might already know to be a quarter, or 1/4. Multiplication of fractions do not require the same denominator, or the bottom number of the fraction, like addition and subtraction does. Instead, you would simply multiply the denominators and the top numerators.

Write out the formula to easily see the equation and the necessary calculation. As an example, you might write:

4/5 x 5/6 = ?

Multiply the numerators together and then the denominators together. In the example, you would multiple 4/5 times 5/6 to get 20/30.

Reduce the fraction by factoring out common multiples. In the example, both numbers are divisible by 10, so you can divide them both by 10 and use the result -- 2/3.