The idea, step by step
Parts that belong together
A number bond shows parts that make a whole. Six and four make ten. We can write 6 + 4 = 10.
If you move one counter from one part to the other, the whole stays the same. Six and four can become seven and three.
Use bonds you know
The parts can be joined in either order: 6 + 4 and 4 + 6 both make ten.
For a larger whole, keep a ten together. Ten and six make sixteen. Eight and twelve make twenty.
A common trap
Thinking changing the order changes the total.
Instead: Joining the same two parts gives the same whole, whichever part you name first.
See the thinking
A bond to ten
What goes with seven to make ten?
- Start with seven counters.
- Count on to ten: eight, nine, ten.
- Three more counters were needed.
A bond to twenty
There are twelve red counters and eight blue counters. How many altogether?
- Twelve is ten and two.
- Two and eight make another ten.
- Ten and ten make twenty.
Check your understanding
What goes with nine to make ten?
Show answer
1
Nine and one make ten.
Your turn
6 questions · Work at your own pace.
Read the questions online
- Complete: 6 + __ = 10.
- Complete: 10 + __ = 16.
- Complete: 8 + 2 = __.
- Write the same bond in the other order: 5 + 7 = 12.
- Complete: 9 + __ = 20.
- Luca says 4 + 6 = 10 but 6 + 4 = 11. Explain the mistake.
Read the worked solutions
- Complete: 6 + __ = 10.
Count on from six: seven, eight, nine, ten.
4 - Complete: 10 + __ = 16.
Sixteen is ten and six.
6 - Complete: 8 + 2 = __.
Eight and two make ten.
10 - Write the same bond in the other order: 5 + 7 = 12.
The same parts still make twelve.
7 + 5 = 12. - Complete: 9 + __ = 20.
Nine and one make ten; another ten makes twenty.
11 - Luca says 4 + 6 = 10 but 6 + 4 = 11. Explain the mistake.
The parts are the same; only their order changed.
Both sums are 10.
Curriculum reference & lesson scope
Australian Curriculum v9 and SA Curriculum Mathematics
Year 1 additive situations and number bonds within twenty.
Official curriculum source ↗