Some people can calculate mentally far quicker than others. One of the reasons for this is that they use clever skills, or ‘tricks’, to help them. Today we look at some of these ‘tricks’ for Years 2, 3 and 4, which all help with fast mental addition and subtraction.

These tutorials are all really clear and concentrate on just one skill, allowing for unlimited practice.

In Year 2 we look at adding and subtracting 9. To add 9, we can add 10 and subtract 1. To subtract 9, we can subtract 10 and add 1.

In Year 3 a similar method is used to add and subtract 99. To add 99, we can add 100 and subtract 1. To subtract 99, we can subtract 100 and add 1.

Again, in Year 4 what might look like a tricky calculation can be done easily by using the same method. To add 999, we can add 1,000 and subtract 1. To subtract 999, we can subtract 1,000 and add 1. This can be taken further by adding 1,000 and subtracting 2 to add 998, and so on.

Year 2 Addition

Year 2 Subtraction

Year 3 Addition

Year 3 Subtraction

Year 4 Addition

Year 4 Subtraction