Let's solve the
Number Bonds to 20 worksheet step by step.
Each diagram shows a number (20) at the top, with two circles below connected to it. The rule is:
>
The sum of the two numbers in the circles must equal 20.
So, if one number is given, we find the missing number by subtracting the known number from 20.
---
Let's go through each one:
#### Row 1:
1. 4 + ? = 20 → ? =
16
2. ? + 3 = 20 → ? =
17
3. 5 + ? = 20 → ? =
15
4. 8 + ? = 20 → ? =
12
#### Row 2:
5. 11 + ? = 20 → ? =
9
6. ? + 6 = 20 → ? =
14
7. 2 + ? = 20 → ? =
18
8. ? + 13 = 20 → ? =
7
#### Row 3:
9. 12 + ? = 20 → ? =
8
10. 19 + ? = 20 → ? =
1
11. ? + 20 = 20 → ? =
0
12. 10 + ? = 20 → ? =
10
#### Row 4:
13. ? + 14 = 20 → ? =
6
14. ? + 16 = 20 → ? =
4
15. 11 + ? = 20 → ? =
9
16. ? + 0 = 20 → ? =
20
---
Final Answers (in order):
```
Row 1: 16, 17, 15, 12
Row 2: 9, 14, 18, 7
Row 3: 8, 1, 0, 10
Row 4: 6, 4, 9, 20
```
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Summary Table:
| Problem | Missing Number |
|--------|----------------|
| 20 = 4 + ? | 16 |
| 20 = ? + 3 | 17 |
| 20 = 5 + ? | 15 |
| 20 = 8 + ? | 12 |
| 20 = 11 + ? | 9 |
| 20 = ? + 6 | 14 |
| 20 = 2 + ? | 18 |
| 20 = ? + 13 | 7 |
| 20 = 12 + ? | 8 |
| 20 = 19 + ? | 1 |
| 20 = ? + 20 | 0 |
| 20 = 10 + ? | 10 |
| 20 = ? + 14 | 6 |
| 20 = ? + 16 | 4 |
| 20 = 11 + ? | 9 |
| 20 = ? + 0 | 20 |
✔ All missing numbers are now filled in correctly!
This exercise helps build fluency in addition and subtraction facts up to 20, which is essential for mental math skills.
Let me know if you'd like a printable version or a visual solution!
Parent Tip: Review the logic above to help your child master the concept of addition number bond worksheet.
