BACK TO WORKSHEETS
This worksheet is about adding and subtracting fractions with different denominators.
Example
When adding or subtracting fractions we begin by finding the lowest common multiple (LCM) of both denominators.
First find the LCM of 24 and 15.
| 24 | 48 | 96 | 120 | ... | ||||
| 15 | 30 | 45 | 60 | 75 | 90 | 105 | 120 | ... |
The LCM is 120.
120 = 5 x 24
and
120 = 8 x 15
| 19 | - | 8 | = | 19 x 5 | - | 8 x 8 | = | 95 - 64 | = | 31 |
| 24 | 15 | 24 x 5 | 15 x 8 | 120 | 120 |
Answers in this worksheet should be given as reduced fractions, written with a / sign, e.g. 7/18
Leave fractions as top-heavy, but write integers as whole numbers (i.e. 5 not 5/1)
