For your exam, you will need to feel confident when dealing with fractions. This section will help you to recognise equivalent fractions and practise simple calculations.
Adding and subtracting fractions
It is easy to add fractions when the numbers on the bottom are the same.
All you need to do is add the tops of the fractions together.
So 2/9 + 5/9 = 7/9
Sometimes you need to cancel down the answer to its simplest terms.
3/10 + 1/10 = 4/10 = 2/5
When the numbers on the bottom are not the same to start with, you use equivalent fractions to make them the same.
- Question
3/5 + 1/4
- Answer
The numbers on the bottom of the fractions are not the same. You can use equivalent fractions to make them both equal 20.
3/5 = 12/20 and 1/4 = 5/20
Now you can add them together.
12/20 + 5/20 = 17/20
Subtraction
You subtract using the same methods you use for adding.
- Question
Calculate: 3/5 - 1/5
- Answer
3/5 - 1/5 = 2/5
- Question
Calculate5/8 - 3/10
- Answer
8 and 10 both divide into 40. So re-write the fractions using 40 as the number on the bottom of each one.
5/8 - 3/10 = 25/40 - 12/40 = 13/40
Links
© MMIX