Simplifying fractions
You learn to write a fraction as simply as possible, without it becoming smaller or bigger.
How to work it out
- Find a common factor.
- Divide the numerator and denominator by that factor.
- Repeat if possible.
24
A worked example
24 = ?
- Find a number that both 2 and 4 can be divided by: 2.
- Divide the top: 2 ÷ 2 = 1.
- Divide the bottom: 4 ÷ 2 = 2.
- It is 12.
More examples
69 = ?
- Find a number that both 6 and 9 can be divided by: 3.
- Divide the top: 6 ÷ 3 = 2.
- Divide the bottom: 9 ÷ 3 = 3.
- It is 23.
69
812 = ?
- Divide the top and the bottom by 2: 812 becomes 46.
- You can do it again: divide by 2 again, and 46 becomes 23.
- It is 23.
812
Watch out
You only divide the number above the line: 68 becomes 38.
Whatever you do to the top, do to the bottom too. Otherwise the fraction changes.
You stop too early: 812 becomes 46.
Check whether the top and the bottom can be divided by the same number again. With 46 they still can: by 2.
Tips
- Find a number whose times table has both numbers in it: for 6 and 9 that is 3.
Exceptions
- If the top and the bottom can only be divided by 1, like in 35, the fraction is already as simple as it gets.
Why it works
When you divide the top and the bottom by the same number, the pieces get bigger and there are fewer of them. The shaded part of the strip stays exactly the same size. Only the name gets shorter: 24 and 12 are the same piece.