Children always seem very reluctant to check the answers to calculations that they have made. This sometimes results in bizarre answers, often when using a calculator.

Here is a simple subtraction worksheet but it also asks for each subtraction to be checked by carrying an addition.

For example: 40 - 17 = 23 can be checked by adding 17 and 23 which equals 40.

The most comon error that children make with this is to say that 40 -17 = 33.

Free Y4 maths worksheet: checking answers to subtraction