Show that addition of two numbers can be done in any order (commutative) and subtraction of one number from another cannot
Inverse Operations - Addition and Subtraction
I designed this resource to help children to visualise the relationship between addition and subtraction. They can then use this relationship to solve missing number problems. There are a wide range of levels, from adding within 20 to using a calculator to add and subtract 5 digit numbers and decimals.
A fun game to practise mental addition skills. The game was designed to cover all the mental addition objectives in the new math curriculum. You can choose one objective, or choose all the objectives for a year group.
This game, together with all the other crystal crash games, is available as a single iPad or Android app.