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 10 to make 30?
10 · 30 · Complements to 10, 20 & 100
2. How many more do you need to add to 62 to make 100?
62 · 100 · 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 1 to make 30?
1 · 30 · Complements to 10, 20 & 100
5. How many more do you need to add to 27 to make 50?
27 · 50 · Complements to 10, 20 & 100
6. How many more do you need to add to 69 to make 100?
69 · 100 · Complements to 10, 20 & 100
7. How many more do you need to add to 10 to make 100?
10 · 100 · Complements to 10, 20 & 100
8. How many more do you need to add to 35 to make 50?
35 · 50 · Complements to 10, 20 & 100
9. How many more do you need to add to 34 to make 100?
34 · 100 · Complements to 10, 20 & 100
10. How many more do you need to add to 41 to make 50?
41 · 50 · Complements to 10, 20 & 100
11. How many more do you need to add to 17 to make 20?
17 · 20 · Complements to 10, 20 & 100
12. How many more do you need to add to 13 to make 30?
13 · 30 · Complements to 10, 20 & 100

12 questions · Seed 104737 · 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 10 to make 30?
20
Subtract 10 from 30: 30 − 10 = 20.
2. How many more do you need to add to 62 to make 100?
38
Subtract 62 from 100: 100 − 62 = 38.
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 1 to make 30?
29
Subtract 1 from 30: 30 − 1 = 29.
5. How many more do you need to add to 27 to make 50?
23
Subtract 27 from 50: 50 − 27 = 23.
6. How many more do you need to add to 69 to make 100?
31
Subtract 69 from 100: 100 − 69 = 31.
7. How many more do you need to add to 10 to make 100?
90
Subtract 10 from 100: 100 − 10 = 90.
8. How many more do you need to add to 35 to make 50?
15
Subtract 35 from 50: 50 − 35 = 15.
9. How many more do you need to add to 34 to make 100?
66
Subtract 34 from 100: 100 − 34 = 66.
10. How many more do you need to add to 41 to make 50?
9
Subtract 41 from 50: 50 − 41 = 9.
11. How many more do you need to add to 17 to make 20?
3
Subtract 17 from 20: 20 − 17 = 3.
12. How many more do you need to add to 13 to make 30?
17
Subtract 13 from 30: 30 − 13 = 17.

12 questions · Seed 104737 · 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 10 to make 30?
10 · 30 · Complements to 10, 20 & 100
2. How many more do you need to add to 62 to make 100?
62 · 100 · 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 1 to make 30?
1 · 30 · Complements to 10, 20 & 100
5. How many more do you need to add to 27 to make 50?
27 · 50 · Complements to 10, 20 & 100
6. How many more do you need to add to 69 to make 100?
69 · 100 · Complements to 10, 20 & 100
7. How many more do you need to add to 10 to make 100?
10 · 100 · Complements to 10, 20 & 100
8. How many more do you need to add to 35 to make 50?
35 · 50 · Complements to 10, 20 & 100
9. How many more do you need to add to 34 to make 100?
34 · 100 · Complements to 10, 20 & 100
10. How many more do you need to add to 41 to make 50?
41 · 50 · Complements to 10, 20 & 100
11. How many more do you need to add to 17 to make 20?
17 · 20 · Complements to 10, 20 & 100
12. How many more do you need to add to 13 to make 30?
13 · 30 · Complements to 10, 20 & 100

12 questions · Seed 104737 · 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 10 to make 30?
20
Subtract 10 from 30: 30 − 10 = 20.
2. How many more do you need to add to 62 to make 100?
38
Subtract 62 from 100: 100 − 62 = 38.
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 1 to make 30?
29
Subtract 1 from 30: 30 − 1 = 29.
5. How many more do you need to add to 27 to make 50?
23
Subtract 27 from 50: 50 − 27 = 23.
6. How many more do you need to add to 69 to make 100?
31
Subtract 69 from 100: 100 − 69 = 31.
7. How many more do you need to add to 10 to make 100?
90
Subtract 10 from 100: 100 − 10 = 90.
8. How many more do you need to add to 35 to make 50?
15
Subtract 35 from 50: 50 − 35 = 15.
9. How many more do you need to add to 34 to make 100?
66
Subtract 34 from 100: 100 − 34 = 66.
10. How many more do you need to add to 41 to make 50?
9
Subtract 41 from 50: 50 − 41 = 9.
11. How many more do you need to add to 17 to make 20?
3
Subtract 17 from 20: 20 − 17 = 3.
12. How many more do you need to add to 13 to make 30?
17
Subtract 13 from 30: 30 − 13 = 17.

12 questions · Seed 104737 · Age guidance, not curriculum certification