New Maths Curriculum (2014): Year 2 objectives.

Pupils should extend their understanding of the language of addition and subtraction to include sum and difference.

Pupils should practise addition and subtraction to 20 to become increasingly fluent in deriving facts such as using 3 + 7 = 10, 10 - 7 = 3 and 7 = 10 - 3 to calculate 30 + 70 = 100, 100 - 70 = 30 and 70 = 100 - 30. They should check their calculations, including by adding to check subtraction and adding numbers in a different order to check addition (e.g. 5 + 2 + 1 = 1 + 5 + 2 = 1 + 2 + 5).

Recording addition and subtraction in columns supports place value and prepares for efficient written methods with larger numbers.