Subtracting a single digit from a 3-digit number, starting with multiples of 100.

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'.

A reminder that subtraction is the inverse of addition, and how this can be useful when working out mental calculations.

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.