Understand How to Add and Subtract Fractions

In this activity, we will add and subtract fractions.

 

The easiest ones to add are when the denominators are the same.

We can just add the numerators:

Like this one:-

 

Easy!!!!

 

 

If the denominator is not the same, we need to do this before we can add or subtract the numerators!

 

In short, we need to find equivalent fractions with the same denominator!

 

Example
 

 

Method

Here, we cannot add tenths and fifths together.

We look for the lowest common multiple of the denominators 10 and 5 = 10

The first one is already in tenths, so we need to multiply the second one by 2

 

 

Now we can add (or subtract if we are asked):

 

 

We can even simplify again by dividing through by 5:

 

Let's have a go at some questions now.