When adding and subtracting fractions, the bottom number of the fraction or the denominator has to be the same in both fractions.

Ex:

5/8 + 1/2

So to add these two fractions you need to have the same denominator. To achieve this you look for the smallest number that both 8 and 2 will go into. In this case, it is 16. Many time the common denominator will be the two numbers multiplied together.

So the next step is to change the fractions by multiplying the numerator and denominator by the number that will make the denominator equal to 16 :

2 5 8 1 10 8

__ * __ + __ * __ this equals: __ + __

2 8 8 2 16 16

Now that the denominator is the same, you can easily add the fractions: 18/16

You can reduce this fraction by dividing 2 into the numerator and denominator: 9/8

With this particular example, it ended up being an improper fraction so you can further simplify it by making it a proper fraction: 1 and 1/8 (one and one eighth)

Let me know if you need further help on this subject