The programmes of study for mathematics are set out year-by-year for key stages 1 and 2. These are the statutory requirements for the new National curriculum in England.
More detailed information can be found at the following government website:
The National curriculum for mathematics aims to ensure that all pupils:
The expectation is that the majority of pupils will move through the programmes of study at broadly the same pace. However, decisions about when to progress are always based on the security of pupils’ understanding and their readiness to progress to the next stage. Pupils who grasp concepts rapidly will be challenged through being offered rich and sophisticated problem before any acceleration through new content. Those who are not sufficiently fluent with earlier material will need to consolidate their understanding through additional practice, before moving on.