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 14 to make 50?
14 · 50 · Complements to 10, 20 & 100
2. How many more do you need to add to 19 to make 30?
19 · 30 · Complements to 10, 20 & 100
3. How many more do you need to add to 7 to make 30?
7 · 30 · Complements to 10, 20 & 100
4. How many more do you need to add to 8 to make 20?
8 · 20 · Complements to 10, 20 & 100
5. How many more do you need to add to 32 to make 50?
32 · 50 · Complements to 10, 20 & 100
6. How many more do you need to add to 17 to make 30?
17 · 30 · Complements to 10, 20 & 100
7. How many more do you need to add to 26 to make 100?
26 · 100 · Complements to 10, 20 & 100
8. How many more do you need to add to 59 to make 100?
59 · 100 · Complements to 10, 20 & 100
9. How many more do you need to add to 11 to make 30?
11 · 30 · Complements to 10, 20 & 100
10. How many more do you need to add to 4 to make 30?
4 · 30 · Complements to 10, 20 & 100
11. How many more do you need to add to 4 to make 20?
4 · 20 · Complements to 10, 20 & 100
12. How many more do you need to add to 23 to make 50?
23 · 50 · Complements to 10, 20 & 100

12 questions · Seed 104736 · 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 14 to make 50?
36
Subtract 14 from 50: 50 − 14 = 36.
2. How many more do you need to add to 19 to make 30?
11
Subtract 19 from 30: 30 − 19 = 11.
3. How many more do you need to add to 7 to make 30?
23
Subtract 7 from 30: 30 − 7 = 23.
4. How many more do you need to add to 8 to make 20?
12
Subtract 8 from 20: 20 − 8 = 12.
5. How many more do you need to add to 32 to make 50?
18
Subtract 32 from 50: 50 − 32 = 18.
6. How many more do you need to add to 17 to make 30?
13
Subtract 17 from 30: 30 − 17 = 13.
7. How many more do you need to add to 26 to make 100?
74
Subtract 26 from 100: 100 − 26 = 74.
8. How many more do you need to add to 59 to make 100?
41
Subtract 59 from 100: 100 − 59 = 41.
9. How many more do you need to add to 11 to make 30?
19
Subtract 11 from 30: 30 − 11 = 19.
10. How many more do you need to add to 4 to make 30?
26
Subtract 4 from 30: 30 − 4 = 26.
11. How many more do you need to add to 4 to make 20?
16
Subtract 4 from 20: 20 − 4 = 16.
12. How many more do you need to add to 23 to make 50?
27
Subtract 23 from 50: 50 − 23 = 27.

12 questions · Seed 104736 · 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 14 to make 50?
14 · 50 · Complements to 10, 20 & 100
2. How many more do you need to add to 19 to make 30?
19 · 30 · Complements to 10, 20 & 100
3. How many more do you need to add to 7 to make 30?
7 · 30 · Complements to 10, 20 & 100
4. How many more do you need to add to 8 to make 20?
8 · 20 · Complements to 10, 20 & 100
5. How many more do you need to add to 32 to make 50?
32 · 50 · Complements to 10, 20 & 100
6. How many more do you need to add to 17 to make 30?
17 · 30 · Complements to 10, 20 & 100
7. How many more do you need to add to 26 to make 100?
26 · 100 · Complements to 10, 20 & 100
8. How many more do you need to add to 59 to make 100?
59 · 100 · Complements to 10, 20 & 100
9. How many more do you need to add to 11 to make 30?
11 · 30 · Complements to 10, 20 & 100
10. How many more do you need to add to 4 to make 30?
4 · 30 · Complements to 10, 20 & 100
11. How many more do you need to add to 4 to make 20?
4 · 20 · Complements to 10, 20 & 100
12. How many more do you need to add to 23 to make 50?
23 · 50 · Complements to 10, 20 & 100

12 questions · Seed 104736 · 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 14 to make 50?
36
Subtract 14 from 50: 50 − 14 = 36.
2. How many more do you need to add to 19 to make 30?
11
Subtract 19 from 30: 30 − 19 = 11.
3. How many more do you need to add to 7 to make 30?
23
Subtract 7 from 30: 30 − 7 = 23.
4. How many more do you need to add to 8 to make 20?
12
Subtract 8 from 20: 20 − 8 = 12.
5. How many more do you need to add to 32 to make 50?
18
Subtract 32 from 50: 50 − 32 = 18.
6. How many more do you need to add to 17 to make 30?
13
Subtract 17 from 30: 30 − 17 = 13.
7. How many more do you need to add to 26 to make 100?
74
Subtract 26 from 100: 100 − 26 = 74.
8. How many more do you need to add to 59 to make 100?
41
Subtract 59 from 100: 100 − 59 = 41.
9. How many more do you need to add to 11 to make 30?
19
Subtract 11 from 30: 30 − 11 = 19.
10. How many more do you need to add to 4 to make 30?
26
Subtract 4 from 30: 30 − 4 = 26.
11. How many more do you need to add to 4 to make 20?
16
Subtract 4 from 20: 20 − 4 = 16.
12. How many more do you need to add to 23 to make 50?
27
Subtract 23 from 50: 50 − 23 = 27.

12 questions · Seed 104736 · Age guidance, not curriculum certification