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 24 to make 30?
24 · 30 · Complements to 10, 20 & 100
2. How many more do you need to add to 33 to make 50?
33 · 50 · Complements to 10, 20 & 100
3. How many more do you need to add to 46 to make 50?
46 · 50 · Complements to 10, 20 & 100
4. How many more do you need to add to 9 to make 30?
9 · 30 · Complements to 10, 20 & 100
5. How many more do you need to add to 49 to make 50?
49 · 50 · Complements to 10, 20 & 100
6. How many more do you need to add to 10 to make 20?
10 · 20 · Complements to 10, 20 & 100
7. How many more do you need to add to 16 to make 30?
16 · 30 · Complements to 10, 20 & 100
8. How many more do you need to add to 17 to make 50?
17 · 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 11 to make 20?
11 · 20 · Complements to 10, 20 & 100
11. How many more do you need to add to 6 to make 20?
6 · 20 · Complements to 10, 20 & 100
12. How many more do you need to add to 62 to make 100?
62 · 100 · Complements to 10, 20 & 100

12 questions · Seed 104769 · 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 24 to make 30?
6
Subtract 24 from 30: 30 − 24 = 6.
2. How many more do you need to add to 33 to make 50?
17
Subtract 33 from 50: 50 − 33 = 17.
3. How many more do you need to add to 46 to make 50?
4
Subtract 46 from 50: 50 − 46 = 4.
4. How many more do you need to add to 9 to make 30?
21
Subtract 9 from 30: 30 − 9 = 21.
5. How many more do you need to add to 49 to make 50?
1
Subtract 49 from 50: 50 − 49 = 1.
6. How many more do you need to add to 10 to make 20?
10
Subtract 10 from 20: 20 − 10 = 10.
7. How many more do you need to add to 16 to make 30?
14
Subtract 16 from 30: 30 − 16 = 14.
8. How many more do you need to add to 17 to make 50?
33
Subtract 17 from 50: 50 − 17 = 33.
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 11 to make 20?
9
Subtract 11 from 20: 20 − 11 = 9.
11. How many more do you need to add to 6 to make 20?
14
Subtract 6 from 20: 20 − 6 = 14.
12. How many more do you need to add to 62 to make 100?
38
Subtract 62 from 100: 100 − 62 = 38.

12 questions · Seed 104769 · 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 24 to make 30?
24 · 30 · Complements to 10, 20 & 100
2. How many more do you need to add to 33 to make 50?
33 · 50 · Complements to 10, 20 & 100
3. How many more do you need to add to 46 to make 50?
46 · 50 · Complements to 10, 20 & 100
4. How many more do you need to add to 9 to make 30?
9 · 30 · Complements to 10, 20 & 100
5. How many more do you need to add to 49 to make 50?
49 · 50 · Complements to 10, 20 & 100
6. How many more do you need to add to 10 to make 20?
10 · 20 · Complements to 10, 20 & 100
7. How many more do you need to add to 16 to make 30?
16 · 30 · Complements to 10, 20 & 100
8. How many more do you need to add to 17 to make 50?
17 · 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 11 to make 20?
11 · 20 · Complements to 10, 20 & 100
11. How many more do you need to add to 6 to make 20?
6 · 20 · Complements to 10, 20 & 100
12. How many more do you need to add to 62 to make 100?
62 · 100 · Complements to 10, 20 & 100

12 questions · Seed 104769 · 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 24 to make 30?
6
Subtract 24 from 30: 30 − 24 = 6.
2. How many more do you need to add to 33 to make 50?
17
Subtract 33 from 50: 50 − 33 = 17.
3. How many more do you need to add to 46 to make 50?
4
Subtract 46 from 50: 50 − 46 = 4.
4. How many more do you need to add to 9 to make 30?
21
Subtract 9 from 30: 30 − 9 = 21.
5. How many more do you need to add to 49 to make 50?
1
Subtract 49 from 50: 50 − 49 = 1.
6. How many more do you need to add to 10 to make 20?
10
Subtract 10 from 20: 20 − 10 = 10.
7. How many more do you need to add to 16 to make 30?
14
Subtract 16 from 30: 30 − 16 = 14.
8. How many more do you need to add to 17 to make 50?
33
Subtract 17 from 50: 50 − 17 = 33.
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 11 to make 20?
9
Subtract 11 from 20: 20 − 11 = 9.
11. How many more do you need to add to 6 to make 20?
14
Subtract 6 from 20: 20 − 6 = 14.
12. How many more do you need to add to 62 to make 100?
38
Subtract 62 from 100: 100 − 62 = 38.

12 questions · Seed 104769 · Age guidance, not curriculum certification