Add and Subtract Fractions to Solve Problems

In this activity, we will practise adding and subtracting fractions.

You may be able to count on or back in fractions mentally.

We can also use number lines to help us solve the problems by counting on or counting back.

Let's take a look at this number line to try an addition problem.

To add fractions with the same denominator, we just count on.

Now let's try a subtraction problem.

To subtract fractions with the same denominator, we just count back.

You can draw out a number line if it helps you to answer the questions in this activity, but why not try doing them mentally instead and see how you get on?

Example

What is 3/9 + 2/9?

The two fractions have the same bottom number (denominator) so all we need to do is to add the two top numbers together (the numerators): 3 + 2 = 5

We don't add the bottom numbers - this stays as 9

So, our answer is 5/9

What is 7/6 - 3/6?

The two fractions have the same bottom number (denominator) , so we simply subtract the two top numbers (numerators): 7 - 3 = 4

We don't subtract the bottom numbers - this stays as 6

Our answer is 4/6

Does this make sense? Are you ready to have a go at some questions?