Ten can be split into two parts. When one part is shown, the missing part is the empty spaces in a ten-frame. Knowing the pairs that make ten also answers subtraction: if 7 and 3 make 10, then 10 − 3 = 7 and 10 − 7 = 3.
Explore this idea with maths tools
Maths you can move
Build 8 + 2
Tap two gold counters to fill the ten-frame.
8 in the frame + 2 waiting. The total stays the same.
Words to know
- number bond
- two parts that join to make a whole
- part
- one of the amounts that make up the whole
Worked examples
7 + ? = 10
- 1.Seven boxes are filled.
- 2.Three boxes are empty, so 7 + 3 = 10.
= 3
? + 4 = 10
- 1.Think: 4 and how many more make 10?
- 2.Four and six make ten, so 6 + 4 = 10.
= 6
10 − ? = 8
- 1.Ten take away a number leaves eight.
- 2.8 and 2 make 10, so 2 was taken away: 10 − 2 = 8.
= 2
For parents
Method: Fill a ten-frame
What to say: Show me the part you know. How many more make ten?
Common mistakes:
- Gives the part already shown instead of the missing part.
- Counts on from the known part but counts that starting number too, so the missing part is one too big.
- Stops counting on one step before ten, so the missing part is one too small.
- Adds together the numbers shown in the question, including the total.