Addition Within 10 and 20

In Year 1, children learn to add numbers within 10 and then within 20. They start by combining groups of physical objects (cubes, counters, fingers) and move towards using number lines and written number sentences such as 5 + 3 = 8.

Children explore addition in three formats: standard questions (5 + 3 = ___), missing addend (5 + ___ = 8), and missing first number (___ + 3 = 8). This variety ensures they truly understand what addition means rather than just following a procedure.

By the end of Year 1, children should be able to add single-digit numbers fluently and begin adding a one-digit number to a two-digit number (e.g. 14 + 5). They learn that addition can be done in any order (the commutative law) and start to use this to check their work.

Addition is used in every area of maths and daily life. A child who is confident adding within 20 can handle money, tell the time, measure ingredients, and solve word problems with ease.

More importantly, secure addition skills in Year 1 prevent the anxiety and catch-up work that can snowball in Years 2 and 3. When addition feels easy, children enjoy maths more and are willing to tackle challenges.

1. 1

   Use everyday moments: 'We have 3 apples and buy 4 more -- how many now?'

2. 2

   Let your child use their fingers, counters or a number line -- these are valid strategies, not crutches.

3. 3

   Practise 'counting on' from the bigger number: for 3 + 8, start at 8 and count on 3.

4. 4

   Play dice games where you add two dice together -- simple and effective.

5. 5

   When your child is ready, introduce missing number problems: '6 + ___ = 9'.

6. 6

   Celebrate effort, not speed. Accuracy matters more than being fast at this stage.