How to work out the product of 2 fractions (or 3 fractions).
A simple guide to multiplying two fractions or more!
Working out the multiplication of two fractions is probably one of the easiest fraction topics. To multiply two fractions follow these simple steps:
1. Multiply the top numbers (numerators) of both fractions.
2. Multiply the bottom numbers (denominators) of both fractions.
3. Write these two answers as a fraction and simplify if possible.
As you can see there is no need to make the denominators of both fractions the same – this is only done if you are working out the sum or difference of two fractions. Let’s take a look at some examples that involve the multiplication of fractions:
Example 1
Work out 3/7 × 4/8
1. Multiply the top numbers (numerators) of both fractions.
3 × 4 = 12
2. Multiply the bottom numbers (denominators) of both fractions.
7 × 8 = 56
3. Write these two answers as a fraction and simplify if possible.
12/56 = 3/14 (divide the numerator and denominator by 4).
Example 2
Work out 5/8 × 3/4
1. Multiply the top numbers (numerators) of both fractions.
5 × 3 = 15
2. Multiply the bottom numbers (denominators) of both fractions.
8 × 4 = 32
3. Write these two answers as a fraction and simplify if possible.
15/32
Example 3
Work out 7/12 × 3/9
1. Multiply the top numbers (numerators) of both fractions.
7 × 3 = 21
2. Multiply the bottom numbers (denominators) of both fractions.
12 × 9 = 108
3. Write these two answers as a fraction and simplify if possible.
21/108 = 7/36 (divide the numerator and denominator by 3).
Example 4
Work out 2/3 × 6
6 can be made into a fraction by making it 6/1.
1. Multiply the top numbers (numerators) of both fractions.
2 × 6 = 12
2. Multiply the bottom numbers (denominators) of both fractions.
3 × 1 = 3
3. Write these two answers as a fraction and simplify if possible.
12/3 = 4/1 = 4
Example 5
Work out the product of 2/3, 3/4 and 7/10.
The same method can be applied to 3 fractions. Also remember that multiplication and product are exactly the same process.
1. Multiply the top numbers (numerators) of the three fractions.
2 × 3 × 7 = 42
2. Multiply the bottom numbers (denominators) of the three fractions.
3 × 4 × 10 = 120
3. Write these two answers as a fraction and simplify if possible.
42/120 = 7/20 (divide the numerator and denominator by 6).
For a complete guide to fractions make sure you read this article:
Fraction Help. A complete guide to everything you need to know about fractions in your math exam.