Bar modelling is a powerful visual method of helping children with their calculating. The term is used extensively in Singapore where children make excellent progress with Maths and is now being used more and more in this country. It is a pictorial approach to calculating, using visual models and is a half way step between the starting point of using real world, concrete objects (e.g. 10 cubes and picking up 3 and seeing how many are left) and the abstract algorithm (e.g. 10 − 7 = ?).
It is powerful because it clearly displays the calculation and it avoids words, which can often lead to difficulties. From the evidence it really does seem to help children to understand what it is they are trying to do; something which can get lost if they are presented with written methods too early.
We have published several sets for Year 1 on addition and subtraction up to 20 and two for Year 2 on adding to make 100 and subtracting from 100. Much more to come in the future.