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In this activity, we will be finding the missing number in a calculation.

 

Example

Find the number that makes the calculation correct.

332 + __ = 900

 

Answer

The opposite (inverse) of adding is subtracting.

So we work out 900 - 332 = 568

 

Here is a simpler example:

400 + ___ = 600

 

The inverse operation is:

600 - 400 = 200

The answer is 200

 

Does that make sense?

 

girl thinking

 

Let's practise this skill in the following questions.

10 questions