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 44 to make 50?
44 · 50 · Complements to 10, 20 & 100
2. How many more do you need to add to 3 to make 20?
3 · 20 · Complements to 10, 20 & 100
3. How many more do you need to add to 65 to make 100?
65 · 100 · Complements to 10, 20 & 100
4. How many more do you need to add to 1 to make 30?
1 · 30 · Complements to 10, 20 & 100
5. How many more do you need to add to 17 to make 20?
17 · 20 · Complements to 10, 20 & 100
6. How many more do you need to add to 6 to make 20?
6 · 20 · Complements to 10, 20 & 100
7. How many more do you need to add to 9 to make 20?
9 · 20 · Complements to 10, 20 & 100
8. How many more do you need to add to 72 to make 100?
72 · 100 · Complements to 10, 20 & 100
9. How many more do you need to add to 13 to make 30?
13 · 30 · Complements to 10, 20 & 100
10. How many more do you need to add to 27 to make 50?
27 · 50 · Complements to 10, 20 & 100
11. How many more do you need to add to 66 to make 100?
66 · 100 · Complements to 10, 20 & 100
12. How many more do you need to add to 55 to make 100?
55 · 100 · Complements to 10, 20 & 100

12 questions · Seed 104754 · 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 44 to make 50?
6
Subtract 44 from 50: 50 − 44 = 6.
2. How many more do you need to add to 3 to make 20?
17
Subtract 3 from 20: 20 − 3 = 17.
3. How many more do you need to add to 65 to make 100?
35
Subtract 65 from 100: 100 − 65 = 35.
4. How many more do you need to add to 1 to make 30?
29
Subtract 1 from 30: 30 − 1 = 29.
5. How many more do you need to add to 17 to make 20?
3
Subtract 17 from 20: 20 − 17 = 3.
6. How many more do you need to add to 6 to make 20?
14
Subtract 6 from 20: 20 − 6 = 14.
7. How many more do you need to add to 9 to make 20?
11
Subtract 9 from 20: 20 − 9 = 11.
8. How many more do you need to add to 72 to make 100?
28
Subtract 72 from 100: 100 − 72 = 28.
9. How many more do you need to add to 13 to make 30?
17
Subtract 13 from 30: 30 − 13 = 17.
10. How many more do you need to add to 27 to make 50?
23
Subtract 27 from 50: 50 − 27 = 23.
11. How many more do you need to add to 66 to make 100?
34
Subtract 66 from 100: 100 − 66 = 34.
12. How many more do you need to add to 55 to make 100?
45
Subtract 55 from 100: 100 − 55 = 45.

12 questions · Seed 104754 · 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 44 to make 50?
44 · 50 · Complements to 10, 20 & 100
2. How many more do you need to add to 3 to make 20?
3 · 20 · Complements to 10, 20 & 100
3. How many more do you need to add to 65 to make 100?
65 · 100 · Complements to 10, 20 & 100
4. How many more do you need to add to 1 to make 30?
1 · 30 · Complements to 10, 20 & 100
5. How many more do you need to add to 17 to make 20?
17 · 20 · Complements to 10, 20 & 100
6. How many more do you need to add to 6 to make 20?
6 · 20 · Complements to 10, 20 & 100
7. How many more do you need to add to 9 to make 20?
9 · 20 · Complements to 10, 20 & 100
8. How many more do you need to add to 72 to make 100?
72 · 100 · Complements to 10, 20 & 100
9. How many more do you need to add to 13 to make 30?
13 · 30 · Complements to 10, 20 & 100
10. How many more do you need to add to 27 to make 50?
27 · 50 · Complements to 10, 20 & 100
11. How many more do you need to add to 66 to make 100?
66 · 100 · Complements to 10, 20 & 100
12. How many more do you need to add to 55 to make 100?
55 · 100 · Complements to 10, 20 & 100

12 questions · Seed 104754 · 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 44 to make 50?
6
Subtract 44 from 50: 50 − 44 = 6.
2. How many more do you need to add to 3 to make 20?
17
Subtract 3 from 20: 20 − 3 = 17.
3. How many more do you need to add to 65 to make 100?
35
Subtract 65 from 100: 100 − 65 = 35.
4. How many more do you need to add to 1 to make 30?
29
Subtract 1 from 30: 30 − 1 = 29.
5. How many more do you need to add to 17 to make 20?
3
Subtract 17 from 20: 20 − 17 = 3.
6. How many more do you need to add to 6 to make 20?
14
Subtract 6 from 20: 20 − 6 = 14.
7. How many more do you need to add to 9 to make 20?
11
Subtract 9 from 20: 20 − 9 = 11.
8. How many more do you need to add to 72 to make 100?
28
Subtract 72 from 100: 100 − 72 = 28.
9. How many more do you need to add to 13 to make 30?
17
Subtract 13 from 30: 30 − 13 = 17.
10. How many more do you need to add to 27 to make 50?
23
Subtract 27 from 50: 50 − 27 = 23.
11. How many more do you need to add to 66 to make 100?
34
Subtract 66 from 100: 100 − 66 = 34.
12. How many more do you need to add to 55 to make 100?
45
Subtract 55 from 100: 100 − 55 = 45.

12 questions · Seed 104754 · Age guidance, not curriculum certification