Use Addition or Subtraction to Find the Missing Number

This activity is about finding the missing number in adding sums.

Example

Find the value of the missing number.

Answer

We need to find the difference between 25 and 28.

We can turn this into a subtraction problem and work it out by doing 28 - 25 = 3

Or we can count on from 25.....26, 27, 28 ........ that's 3 numbers.

So, the answer is 3

You can see that there is often more than one way of finding the answer to a maths problem. The important thing is to choose the way that works best for you.

Which of these ways do you find easier?