MathsAges 7-9

Complements to 10, 20 & 100

Find how many more are needed to complete a benchmark number such as 10, 20, 50 or 100. Review suitability for your learners before teaching.

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Worksheet StudioPractice pack · Ages 7-9

Take your time. Show your thinking.

1. How many more do you need to add to 32 to make 100?
32 · 100 · Complements to 10, 20 & 100
2. How many more do you need to add to 4 to make 20?
4 · 20 · Complements to 10, 20 & 100
3. How many more do you need to add to 2 to make 30?
2 · 30 · Complements to 10, 20 & 100
4. How many more do you need to add to 10 to make 20?
10 · 20 · Complements to 10, 20 & 100
5. How many more do you need to add to 14 to make 30?
14 · 30 · Complements to 10, 20 & 100
6. How many more do you need to add to 31 to make 100?
31 · 100 · Complements to 10, 20 & 100
7. How many more do you need to add to 13 to make 100?
13 · 100 · Complements to 10, 20 & 100
8. How many more do you need to add to 26 to make 30?
26 · 30 · Complements to 10, 20 & 100
9. How many more do you need to add to 89 to make 100?
89 · 100 · Complements to 10, 20 & 100
10. How many more do you need to add to 19 to make 30?
19 · 30 · Complements to 10, 20 & 100
11. How many more do you need to add to 20 to make 100?
20 · 100 · Complements to 10, 20 & 100
12. How many more do you need to add to 73 to make 100?
73 · 100 · Complements to 10, 20 & 100

12 questions · Seed 104741 · Age guidance, not curriculum certification

View the answer key

Worksheet StudioAnswer key · Ages 7-9

Answers and reasoning. Review before teaching.

1. How many more do you need to add to 32 to make 100?
68
Subtract 32 from 100: 100 − 32 = 68.
2. How many more do you need to add to 4 to make 20?
16
Subtract 4 from 20: 20 − 4 = 16.
3. How many more do you need to add to 2 to make 30?
28
Subtract 2 from 30: 30 − 2 = 28.
4. How many more do you need to add to 10 to make 20?
10
Subtract 10 from 20: 20 − 10 = 10.
5. How many more do you need to add to 14 to make 30?
16
Subtract 14 from 30: 30 − 14 = 16.
6. How many more do you need to add to 31 to make 100?
69
Subtract 31 from 100: 100 − 31 = 69.
7. How many more do you need to add to 13 to make 100?
87
Subtract 13 from 100: 100 − 13 = 87.
8. How many more do you need to add to 26 to make 30?
4
Subtract 26 from 30: 30 − 26 = 4.
9. How many more do you need to add to 89 to make 100?
11
Subtract 89 from 100: 100 − 89 = 11.
10. How many more do you need to add to 19 to make 30?
11
Subtract 19 from 30: 30 − 19 = 11.
11. How many more do you need to add to 20 to make 100?
80
Subtract 20 from 100: 100 − 20 = 80.
12. How many more do you need to add to 73 to make 100?
27
Subtract 73 from 100: 100 − 73 = 27.

12 questions · Seed 104741 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 7-9

Take your time. Show your thinking.

1. How many more do you need to add to 32 to make 100?
32 · 100 · Complements to 10, 20 & 100
2. How many more do you need to add to 4 to make 20?
4 · 20 · Complements to 10, 20 & 100
3. How many more do you need to add to 2 to make 30?
2 · 30 · Complements to 10, 20 & 100
4. How many more do you need to add to 10 to make 20?
10 · 20 · Complements to 10, 20 & 100
5. How many more do you need to add to 14 to make 30?
14 · 30 · Complements to 10, 20 & 100
6. How many more do you need to add to 31 to make 100?
31 · 100 · Complements to 10, 20 & 100
7. How many more do you need to add to 13 to make 100?
13 · 100 · Complements to 10, 20 & 100
8. How many more do you need to add to 26 to make 30?
26 · 30 · Complements to 10, 20 & 100
9. How many more do you need to add to 89 to make 100?
89 · 100 · Complements to 10, 20 & 100
10. How many more do you need to add to 19 to make 30?
19 · 30 · Complements to 10, 20 & 100
11. How many more do you need to add to 20 to make 100?
20 · 100 · Complements to 10, 20 & 100
12. How many more do you need to add to 73 to make 100?
73 · 100 · Complements to 10, 20 & 100

12 questions · Seed 104741 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 7-9

Answers and reasoning. Review before teaching.

1. How many more do you need to add to 32 to make 100?
68
Subtract 32 from 100: 100 − 32 = 68.
2. How many more do you need to add to 4 to make 20?
16
Subtract 4 from 20: 20 − 4 = 16.
3. How many more do you need to add to 2 to make 30?
28
Subtract 2 from 30: 30 − 2 = 28.
4. How many more do you need to add to 10 to make 20?
10
Subtract 10 from 20: 20 − 10 = 10.
5. How many more do you need to add to 14 to make 30?
16
Subtract 14 from 30: 30 − 14 = 16.
6. How many more do you need to add to 31 to make 100?
69
Subtract 31 from 100: 100 − 31 = 69.
7. How many more do you need to add to 13 to make 100?
87
Subtract 13 from 100: 100 − 13 = 87.
8. How many more do you need to add to 26 to make 30?
4
Subtract 26 from 30: 30 − 26 = 4.
9. How many more do you need to add to 89 to make 100?
11
Subtract 89 from 100: 100 − 89 = 11.
10. How many more do you need to add to 19 to make 30?
11
Subtract 19 from 30: 30 − 19 = 11.
11. How many more do you need to add to 20 to make 100?
80
Subtract 20 from 100: 100 − 20 = 80.
12. How many more do you need to add to 73 to make 100?
27
Subtract 73 from 100: 100 − 73 = 27.

12 questions · Seed 104741 · Age guidance, not curriculum certification