Written methods of calculation are based on mental strategies. Each of the four operations builds on mental skills which provide the foundation for jottings and informal written methods of recording. Skills need to be taught, practised and reviewed constantly. These skills lead on to more formal written methods of calculation.
Strategies for calculation need to be supported by familiar models and images to reinforce understanding. When teaching a new strategy it is important to start with numbers that the children can easily manipulate so that they can understand the concept.
The transition between stages should not be hurried as not all children will be ready to move on to the next stage at the same time, therefore the progression in the above documents is outlined in stages. Previous stages may need to be revisited to consolidate understanding when introducing a new strategy.
A sound understanding of the number system is essential for children to carry out calculations efficiently and accurately.