# Addition and subtraction of fractional numbers

We have to look at two cases:

## 1st) equal denominators

To add fractions with equal denominators, just add the numerators and keep the denominator.

- To subtract fractions with equal denominators, just subtract the numerators and keep the denominator.

Take a look at the examples:

## 2) different denominators

To add fractions with different denominators, one solution is to obtain equivalent fractions, with denominators equal to the mmc of the denominators of fractions. Example: Sum the Fractions .

Obtaining the mmc of the denominators we have mmc (5,2) = 10.

 (10:5).4 = 8 (10:2).5 = 25

In short: we use mmc to get the equivalent fractions and then we usually add the fractions, which will already have the same denominator, that is, we use case 1.

Next: Multiplication and Division of Fractional Numbers