Adding & Subtracting Fractions
Adding fractions  It's important to understand that if you multiply the top and bottom of a fraction by the same value then the value of the fraction doesn't change
To add fractions we must have a common denominator, the same number on the bottom of each fraction, we can achieve this by multiplying the whole fraction.
If we are adding 4/5 and 2/10 then we first find the lowest common multiple of the denominators. In this case, it is 6. We would now multiply the first fraction (4/5) by two, making 8/10. Now we have common denominators, we can simply add the two fractions together. 8/10 + 2/10 = 10/10 or 1.
Subtracting Fractions  This goes by the same method but you just subtract the two fractions instead of adding.
Example: 8/15  2/5

2/5 x 3 = 6/15

8/15  6/15 = 2/15

Answer = 2/15