Understand that subtraction is the inverse of addition; state the subtraction corresponding to a given addition and vice versa (NNS Framework for teaching mathematics, Supplement of examples, Section 5, pages 25, 29, 35)

Associated knowledge and skills

Errors and misconceptions

Tracking charts

Teaching sequences and spotlights

Count on and back in ones and tens.

Makes mistakes when counting using teen numbers and/or crossing boundaries.

1 Y2
1 Y2
1 Y2

Identify pairs of numbers that add to twenty and use known number facts to add mentally.

Has difficulty in remembering number pairs totalling between ten and twenty, resulting in calculation errors.

2 Y2
2 Y2
2 Y2

Find a difference by counting up from the smaller to the larger number.

Counts up unreliably; still counting the smaller number to get one too many in the answer.

3 Y2
3 Y2
3 Y2

Recognise subtraction as taking away, finding the difference and complementary addition.

Does not relate finding a difference and complementary addition to the operation of subtraction.

4 Y2
4 Y2
4 Y2

Recognise, for example, that subtracting 13 'undoes' adding 13 and vice versa, and that this means that since 4 + 13 = 17, we can state the inverse that 17 - 13 = 4.

Is insecure in making links between addition and subtraction and/or recognising inverses.

5 Y2
5 Y2
5 Y2

Develop and recognise patterns to help deduce other addition and subtraction facts.

Does not readily use number patterns to support calculating, for example:
46 - 5 = 41, so
46 - 15 = 31,
46 - 25 = 21, etc.

6 Y2
6 Y2
6 Y2