If you were to add and , it is hard to picture what the answer would be. Rewriting the fractions with a common bottom number, or denominator (in this case, ), makes it easier.

Remember, you can only add and subtract fractions when the bottom numbers, or denominators, are the same.

So, to add or subtract fractions:

1. Change the fractions so they have the same denominator.
2. Add or subtract the top numbers, or numerators.

Question

What is ?

## Mixed numbers

To add or subtract mixed numbers, it is usually easiest to change them to improper fractions first and then change the answer back into a mixed number (if needed).

Question

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