1. Addition and Subtraction of Fractions

2. When the Denominators are Equal
If the denominators are equal, add the numerators and place this over the original denominator. EG = 6 7

3. Pictorially
4 7 is the same as 2 7 is the same as Putting these together is: which is 6 7

4. Examples
= − 3 9 = 1 9

5. When the Denominators are Different
This process requires the fractions to be re-written as equivalent ones that end up having the same denominator, then procede as previously.

6. Example
These fractions need to be re-written with a common denominator. The number we are aiming for should be the lowest common multiple of the two original denominators.

7. Example
In this case the lowest common denominator will be 30. So 2 5 × 6 6 = and 1 6 × 5 5 = 5 30

8. Example
Hence = Now precede as earlier, add the numerators together and place the sum above 30. So = = 17 30

9. Example
3 4 − − 1 3 = 9 12 − − 1 3 = 9 12 − 4 12 = 5 12

10. Example
2 3 − − 1 2 = 4 6 − − 1 2 = 4 6 − 3 6 = 1 6