The idea, step by step
Start with a useful part
For 9 + 2, keep nine in your head. Count on two steps: ten, eleven. You do not need to start again at one.
If the larger number comes second, swap the parts: 2 + 9 has the same answer as 9 + 2.
Make ten, then add the rest
Ten is easy to build on. For 8 + 5, split the five into two and three. Put two with eight to make ten.
Add the remaining three to ten. You used all five, so the total is thirteen.
A common trap
Making ten but forgetting the leftover part.
Instead: Split the second part carefully. After making ten, add everything left over.
See the thinking
Count on a little
Find 3 + 11.
- Keep eleven and count on three.
- Say twelve, thirteen, fourteen.
- The answer is fourteen.
Make ten
Find 8 + 5.
- Eight needs two to reach ten.
- Split five into two and three.
- 8 + 5 = 10 + 3 = 13.
Check your understanding
Use make ten for 9 + 4. What is the answer?
Show answer
13
Split four into one and three: nine plus one is ten; add three.
Your turn
6 questions · Work at your own pace.
Read the questions online
- Count on to find 12 + 2.
- Find 2 + 9 by counting on from the larger number.
- Make ten to find 7 + 5.
- Make ten to find 6 + 8.
- Ivy says 8 + 4 = 10 because eight needs two to make ten. What did she forget?
- Find 9 + 6. Show the split you use to make ten.
Read the worked solutions
- Count on to find 12 + 2.
Start at twelve; count thirteen, fourteen.
14 - Find 2 + 9 by counting on from the larger number.
Start at nine; count ten, eleven.
11 - Make ten to find 7 + 5.
Split five into three and two: 7 + 3 + 2 = 12.
12 - Make ten to find 6 + 8.
Six needs four; split eight into four and four: 10 + 4 = 14.
14 - Ivy says 8 + 4 = 10 because eight needs two to make ten. What did she forget?
Four was split into two and two; both parts must be used.
She forgot the other two. The total is 12. - Find 9 + 6. Show the split you use to make ten.
9 + 1 = 10; 10 + 5 = 15.
15; split six into one and five.
Curriculum reference & lesson scope
Australian Curriculum v9 and SA Curriculum Mathematics
Year 1 additive situations and number bonds within twenty.
Official curriculum source ↗