Number bonds are pairs of numbers that add to a chosen whole. For ten, 6 and 4 are one pair: 6 + 4 = 10. You can explore that relationship with counters, pictures, spoken descriptions or written numbers. Counting is a useful way to check a pair while recall develops.
The pairs that make ten
There are six pairs when the order of the parts does not matter. Written in every order, there are 11 expressions; 5 + 5 appears once.
| Addition | Related subtraction |
|---|---|
| 0 + 10 = 10 | 10 − 0 = 1010 − 10 = 0 |
| 1 + 9 = 10 | 10 − 1 = 910 − 9 = 1 |
| 2 + 8 = 10 | 10 − 2 = 810 − 8 = 2 |
| 3 + 7 = 10 | 10 − 3 = 710 − 7 = 3 |
| 4 + 6 = 10 | 10 − 4 = 610 − 6 = 4 |
| 5 + 5 = 10 | 10 − 5 = 5 |
Zero is included. Swapping the two parts keeps the same whole.
Swap the parts and the whole stays the same: 4 + 6 also makes ten. If you write every order separately, there are eleven expressions, because 5 + 5 is the same both ways round. An empty group is still a part: zero and ten belong in the set.
The same relationship helps with subtraction. Six and four make ten, so taking six from ten leaves four, and taking four leaves six. Show this by covering or moving one group rather than expecting an instant verbal answer.
Try one bond together
Use the printable activity card or draw a frame with two rows of five cells. Put ten counters or drawn dots on it. Separate six from four, name or point to the groups, then put them together again. Try seven and three next.
Let the player choose whether to count, point, describe, draw or use a number. One partner can make a group while the other finds what is missing. Swap roles if both want to. There is no required session length or score; a familiar example is a reasonable place to finish and revisit.
Physical objects, a picture and a written sum can be used together. You can return to a representation whenever it helps; the game does not require the player to stop counting or give up a visual hint before continuing.
See the missing part in Ten-Frame Fill
Open Ten-Frame Fill, choose Finish to 10, then Play. The grey counters are fixed starting counters. Tap or click an empty cell to add an orange counter. The whole is ten; fill the remaining cells to complete it. A new starting arrangement follows after the completed frame.
For a different activity, choose Count and a five- or ten-frame. Match the displayed target by adding counters. Tap an added counter again to remove it. An overshoot changes the target colour; it does not take away lives or end the game.
Read the numbers aloud is optional and starts off. The spoken prompts use the site's prepared synthetic speech. Preview sound on your device before a shared session. Cell buttons can also be focused with Tab and activated with Enter or Space; check the complete workflow with the input setup the player uses.
Choose a partner in Bond Pairs
Open Bond Pairs. Choose Bonds to 10, leave Show the ten-frame hint on and select Easy (2 choices). Press Play, then choose the missing partner. For example, if the given part is six, four completes the whole.
In Easy, a wrong tap reveals the correct partner and advances after a short pause. Harder (4 choices) presents four numbers and allows another try on the same question after its feedback. These are different retry behaviours; Easy is not a guarantee that every first answer will be correct.
Say the stem sentence starts off and can be enabled from the menu. It joins prepared synthetic number and phrase clips. The game has no countdown, although feedback advances automatically. Use Menu if you want to pause between examples.
Each correct answer contributes to the existing Bond Pairs stickers. Ten correct answers in a bond family also earn that family's number-bonds sticker; the total carries across visits on the same browser. A sticker records game progress, not an assessment of fluency. Browser storage can be cleared.
The pairs that make twenty
There are eleven pairs when the order of the parts does not matter. Written in every order, there are 21 expressions; 10 + 10 appears once.
| Addition | Related subtraction |
|---|---|
| 0 + 20 = 20 | 20 − 0 = 2020 − 20 = 0 |
| 1 + 19 = 20 | 20 − 1 = 1920 − 19 = 1 |
| 2 + 18 = 20 | 20 − 2 = 1820 − 18 = 2 |
| 3 + 17 = 20 | 20 − 3 = 1720 − 17 = 3 |
| 4 + 16 = 20 | 20 − 4 = 1620 − 16 = 4 |
| 5 + 15 = 20 | 20 − 5 = 1520 − 15 = 5 |
| 6 + 14 = 20 | 20 − 6 = 1420 − 14 = 6 |
| 7 + 13 = 20 | 20 − 7 = 1320 − 13 = 7 |
| 8 + 12 = 20 | 20 − 8 = 1220 − 12 = 8 |
| 9 + 11 = 20 | 20 − 9 = 1120 − 11 = 9 |
| 10 + 10 = 20 | 20 − 10 = 10 |
Zero is included. Swapping the two parts keeps the same whole.
Practise bonds to 20 in Bond Pairs. Twenty is preselected, with two choices and the visual hint on; sound stays off. Choose Play to begin. You can change the family, choices and support from the menu.
From ten to twenty
Keep the whole visible while changing a part: 4 + 6 = 10, so 14 + 6 = 20, and 4 + 16 = 20. Represent the twenty with two ten-frames if that helps. Bond Pairs offers Bonds to 5, Bonds to 10 and Bonds to 20; choose the family that suits the activity rather than treating them as compulsory levels.
For other representations, Rainbow to 10 pairs numbers on a number line, Part-Whole Pop presents the two parts of a whole, and Missing Number leaves a gap in a number sentence. Quick Look practises recognising dot quantities; it is a separate activity, not a prerequisite. Tens Train explores pairs to one hundred in tens.
What the curriculum says
The mathematics programme of study for England includes representing and using number bonds and related subtraction facts within twenty in Year 1. Year 2 includes fluent recall and use of addition and subtraction facts to twenty, with related facts to one hundred. These statements describe curriculum content; they are not a diagnosis or a deadline for an individual learner. Other UK nations have their own curricula. Read the DfE programme of study.
Make the next visit easy
Save a game using its favourite star, or keep the printed card beside your usual device. Both featured games are free browser activities with no signup. Choose sound and visual support together, and stop or change activity when the player wants to. For more shared-play suggestions, visit the family and classroom guide.