Grade 1 · Unit 1: Number and place value

Partitioning

Split numbers into parts to make adding easier.

Splitting into groups

10 sweets can be split into two bowls. Maybe 6 in one bowl and 4 in the other. The two parts make the whole.

Number bonds

A number bond shows a whole and its two parts. 6 + 4 = 10, and 10 − 4 = 6. Bonds to 10 are very useful: 1 + 9, 2 + 8, 3 + 7, 4 + 6, 5 + 5.

Tens and ones parts

We can partition 35 into tens and ones. 35 = 30 + 5. This helps when we add bigger numbers.

Adding by partitioning

24 + 5: split 24 into 20 and 4. Add the ones first: 4 + 5 = 9. Then 20 + 9 = 29.

What I learnt

• I can split a number into two parts.
• I know my number bonds to 10.
• I can partition a 2-digit number into tens and ones.