Most of the subtractions we ever do, we do 'in our heads', not on paper. Even if we use a calculator we should do a quick mental approximate answer to check that we haven't pressed the wrong keys. But, when we subtract 'in our heads' we frequently just add! For example 23 - 19  = 4 I can do quite easily by counting on from 19, adding 1 to make 20, and then 3 to make 23. It's amazing how much can be achieved just from a good knowledge of addition and these pages help children appreciate this. Go to our addition helping subtraction pages