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 4 to make 100?
4 · 100 · Complements to 10, 20 & 100
2. How many more do you need to add to 23 to make 50?
23 · 50 · Complements to 10, 20 & 100
3. How many more do you need to add to 23 to make 100?
23 · 100 · Complements to 10, 20 & 100
4. How many more do you need to add to 39 to make 50?
39 · 50 · Complements to 10, 20 & 100
5. How many more do you need to add to 3 to make 30?
3 · 30 · Complements to 10, 20 & 100
6. How many more do you need to add to 18 to make 20?
18 · 20 · Complements to 10, 20 & 100
7. How many more do you need to add to 1 to make 30?
1 · 30 · Complements to 10, 20 & 100
8. How many more do you need to add to 41 to make 50?
41 · 50 · Complements to 10, 20 & 100
9. How many more do you need to add to 40 to make 50?
40 · 50 · Complements to 10, 20 & 100
10. How many more do you need to add to 44 to make 50?
44 · 50 · Complements to 10, 20 & 100
11. How many more do you need to add to 14 to make 20?
14 · 20 · Complements to 10, 20 & 100
12. How many more do you need to add to 17 to make 30?
17 · 30 · Complements to 10, 20 & 100

12 questions · Seed 104756 · 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 4 to make 100?
96
Subtract 4 from 100: 100 − 4 = 96.
2. How many more do you need to add to 23 to make 50?
27
Subtract 23 from 50: 50 − 23 = 27.
3. How many more do you need to add to 23 to make 100?
77
Subtract 23 from 100: 100 − 23 = 77.
4. How many more do you need to add to 39 to make 50?
11
Subtract 39 from 50: 50 − 39 = 11.
5. How many more do you need to add to 3 to make 30?
27
Subtract 3 from 30: 30 − 3 = 27.
6. How many more do you need to add to 18 to make 20?
2
Subtract 18 from 20: 20 − 18 = 2.
7. How many more do you need to add to 1 to make 30?
29
Subtract 1 from 30: 30 − 1 = 29.
8. How many more do you need to add to 41 to make 50?
9
Subtract 41 from 50: 50 − 41 = 9.
9. How many more do you need to add to 40 to make 50?
10
Subtract 40 from 50: 50 − 40 = 10.
10. How many more do you need to add to 44 to make 50?
6
Subtract 44 from 50: 50 − 44 = 6.
11. How many more do you need to add to 14 to make 20?
6
Subtract 14 from 20: 20 − 14 = 6.
12. How many more do you need to add to 17 to make 30?
13
Subtract 17 from 30: 30 − 17 = 13.

12 questions · Seed 104756 · 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 4 to make 100?
4 · 100 · Complements to 10, 20 & 100
2. How many more do you need to add to 23 to make 50?
23 · 50 · Complements to 10, 20 & 100
3. How many more do you need to add to 23 to make 100?
23 · 100 · Complements to 10, 20 & 100
4. How many more do you need to add to 39 to make 50?
39 · 50 · Complements to 10, 20 & 100
5. How many more do you need to add to 3 to make 30?
3 · 30 · Complements to 10, 20 & 100
6. How many more do you need to add to 18 to make 20?
18 · 20 · Complements to 10, 20 & 100
7. How many more do you need to add to 1 to make 30?
1 · 30 · Complements to 10, 20 & 100
8. How many more do you need to add to 41 to make 50?
41 · 50 · Complements to 10, 20 & 100
9. How many more do you need to add to 40 to make 50?
40 · 50 · Complements to 10, 20 & 100
10. How many more do you need to add to 44 to make 50?
44 · 50 · Complements to 10, 20 & 100
11. How many more do you need to add to 14 to make 20?
14 · 20 · Complements to 10, 20 & 100
12. How many more do you need to add to 17 to make 30?
17 · 30 · Complements to 10, 20 & 100

12 questions · Seed 104756 · 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 4 to make 100?
96
Subtract 4 from 100: 100 − 4 = 96.
2. How many more do you need to add to 23 to make 50?
27
Subtract 23 from 50: 50 − 23 = 27.
3. How many more do you need to add to 23 to make 100?
77
Subtract 23 from 100: 100 − 23 = 77.
4. How many more do you need to add to 39 to make 50?
11
Subtract 39 from 50: 50 − 39 = 11.
5. How many more do you need to add to 3 to make 30?
27
Subtract 3 from 30: 30 − 3 = 27.
6. How many more do you need to add to 18 to make 20?
2
Subtract 18 from 20: 20 − 18 = 2.
7. How many more do you need to add to 1 to make 30?
29
Subtract 1 from 30: 30 − 1 = 29.
8. How many more do you need to add to 41 to make 50?
9
Subtract 41 from 50: 50 − 41 = 9.
9. How many more do you need to add to 40 to make 50?
10
Subtract 40 from 50: 50 − 40 = 10.
10. How many more do you need to add to 44 to make 50?
6
Subtract 44 from 50: 50 − 44 = 6.
11. How many more do you need to add to 14 to make 20?
6
Subtract 14 from 20: 20 − 14 = 6.
12. How many more do you need to add to 17 to make 30?
13
Subtract 17 from 30: 30 − 17 = 13.

12 questions · Seed 104756 · Age guidance, not curriculum certification