Subtracting a single digit from a multiple of 1000. Then, moving on to subtracting two numbers just either side of the thousands boundary. They look tricky but are easy if you 'count on'.

Can you say which of these are true and which are false? A quick test of the relationship between addition and subtraction and what effect zero has.

More adding and taking away 19, 29 etc. Easy if you know how!

Using bar models to help with addition and subtraction word problems.