84 Basic addition and subtraction missing number cards under 20

84 Basic addition and subtraction missing number cards under 20 that I have backed on coloured paper have been so effective with pupils. I have written the answer of each question on the back. They can either write down the answer with a whiteboard marker and check it at the end or practice them verbally with a friend. Another game is to lay out the answer cards and put the question that fits the answer on top. The colours just brighten it up as well, I have chosen to back the answers on a different colour paper as the questions.