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 3 to make 30?
3 · 30 · Complements to 10, 20 & 100
2. How many more do you need to add to 26 to make 30?
26 · 30 · Complements to 10, 20 & 100
3. How many more do you need to add to 15 to make 30?
15 · 30 · Complements to 10, 20 & 100
4. How many more do you need to add to 37 to make 100?
37 · 100 · Complements to 10, 20 & 100
5. How many more do you need to add to 44 to make 50?
44 · 50 · Complements to 10, 20 & 100
6. How many more do you need to add to 17 to make 50?
17 · 50 · Complements to 10, 20 & 100
7. How many more do you need to add to 32 to make 100?
32 · 100 · Complements to 10, 20 & 100
8. How many more do you need to add to 18 to make 50?
18 · 50 · Complements to 10, 20 & 100
9. How many more do you need to add to 5 to make 30?
5 · 30 · Complements to 10, 20 & 100
10. How many more do you need to add to 7 to make 30?
7 · 30 · Complements to 10, 20 & 100
11. How many more do you need to add to 17 to make 30?
17 · 30 · Complements to 10, 20 & 100
12. How many more do you need to add to 4 to make 50?
4 · 50 · Complements to 10, 20 & 100

12 questions · Seed 104748 · 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 3 to make 30?
27
Subtract 3 from 30: 30 − 3 = 27.
2. How many more do you need to add to 26 to make 30?
4
Subtract 26 from 30: 30 − 26 = 4.
3. How many more do you need to add to 15 to make 30?
15
Subtract 15 from 30: 30 − 15 = 15.
4. How many more do you need to add to 37 to make 100?
63
Subtract 37 from 100: 100 − 37 = 63.
5. How many more do you need to add to 44 to make 50?
6
Subtract 44 from 50: 50 − 44 = 6.
6. How many more do you need to add to 17 to make 50?
33
Subtract 17 from 50: 50 − 17 = 33.
7. How many more do you need to add to 32 to make 100?
68
Subtract 32 from 100: 100 − 32 = 68.
8. How many more do you need to add to 18 to make 50?
32
Subtract 18 from 50: 50 − 18 = 32.
9. How many more do you need to add to 5 to make 30?
25
Subtract 5 from 30: 30 − 5 = 25.
10. How many more do you need to add to 7 to make 30?
23
Subtract 7 from 30: 30 − 7 = 23.
11. How many more do you need to add to 17 to make 30?
13
Subtract 17 from 30: 30 − 17 = 13.
12. How many more do you need to add to 4 to make 50?
46
Subtract 4 from 50: 50 − 4 = 46.

12 questions · Seed 104748 · 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 3 to make 30?
3 · 30 · Complements to 10, 20 & 100
2. How many more do you need to add to 26 to make 30?
26 · 30 · Complements to 10, 20 & 100
3. How many more do you need to add to 15 to make 30?
15 · 30 · Complements to 10, 20 & 100
4. How many more do you need to add to 37 to make 100?
37 · 100 · Complements to 10, 20 & 100
5. How many more do you need to add to 44 to make 50?
44 · 50 · Complements to 10, 20 & 100
6. How many more do you need to add to 17 to make 50?
17 · 50 · Complements to 10, 20 & 100
7. How many more do you need to add to 32 to make 100?
32 · 100 · Complements to 10, 20 & 100
8. How many more do you need to add to 18 to make 50?
18 · 50 · Complements to 10, 20 & 100
9. How many more do you need to add to 5 to make 30?
5 · 30 · Complements to 10, 20 & 100
10. How many more do you need to add to 7 to make 30?
7 · 30 · Complements to 10, 20 & 100
11. How many more do you need to add to 17 to make 30?
17 · 30 · Complements to 10, 20 & 100
12. How many more do you need to add to 4 to make 50?
4 · 50 · Complements to 10, 20 & 100

12 questions · Seed 104748 · 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 3 to make 30?
27
Subtract 3 from 30: 30 − 3 = 27.
2. How many more do you need to add to 26 to make 30?
4
Subtract 26 from 30: 30 − 26 = 4.
3. How many more do you need to add to 15 to make 30?
15
Subtract 15 from 30: 30 − 15 = 15.
4. How many more do you need to add to 37 to make 100?
63
Subtract 37 from 100: 100 − 37 = 63.
5. How many more do you need to add to 44 to make 50?
6
Subtract 44 from 50: 50 − 44 = 6.
6. How many more do you need to add to 17 to make 50?
33
Subtract 17 from 50: 50 − 17 = 33.
7. How many more do you need to add to 32 to make 100?
68
Subtract 32 from 100: 100 − 32 = 68.
8. How many more do you need to add to 18 to make 50?
32
Subtract 18 from 50: 50 − 18 = 32.
9. How many more do you need to add to 5 to make 30?
25
Subtract 5 from 30: 30 − 5 = 25.
10. How many more do you need to add to 7 to make 30?
23
Subtract 7 from 30: 30 − 7 = 23.
11. How many more do you need to add to 17 to make 30?
13
Subtract 17 from 30: 30 − 17 = 13.
12. How many more do you need to add to 4 to make 50?
46
Subtract 4 from 50: 50 − 4 = 46.

12 questions · Seed 104748 · Age guidance, not curriculum certification