As the children progress through school, the calculation strategies used change. These are closely linked to the National Curriculum for Mathematics and the age related outcomes for each Year group.
Starting at Early Years through to Year 6, the children work through the subtraction stages. These are progressive and the skills taught link and build up through the stages.
Mr Evans, our lead teacher for Mathematics, has produced a series of learning tutorials to support both parents/guardians, as well as children to understand the subtraction stages.
Subtraction - Stage 1 (Year 1 end of year expectation)
This subtraction method uses physical objects to take away and is an expected outcome for children in Year 1.
Subtraction - Stage 2 (Year 1 end of year expectation)
This approach uses a numbered number line to help the children count up to a number, in order to calculate the difference.
Subtraction - Stage 3
Stage 3 utilises a blank number line and encourages children to jump in multiples of ten to solve a calculation more efficiently. This method should be secure by the end of Year 2.
Subtraction - Stage 4
Stage 4 introduces the concept of column subtraction, but in an expanded form. The expanded form appears complicated, however this method is crucial in ensuring children develop a secure understanding of the place value of numbers. Without this understanding, they will struggle to solve reasoning problems as they will only have an understanding of how to use the method, rather than the maths involved in it.
Subtraction - Stage 5
Subtraction - Stage 6
In stage 6, children continue to use the standard column method, but with larger numbers. They will also progress to using this method to subtract decimal numbers of different sizes. This stage introduces the concept of a place holder.
Subtraction - Bonus Method
This is a really effective trick that can be applied in all year groups. When faced with a question involving calculating change, for example I spend £7.78 and I pay with a £10 note, how much change do I receive, or 2000 - 1779, many children will immediately apply a column subtraction method. This works, but it involves a lot of exchanging which provides many opportunities to make a mistake. This bonus method provides a little trick to help make these style of calculations a LOT easier.