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 33 to make 50?
33 · 50 · Complements to 10, 20 & 100
2. How many more do you need to add to 13 to make 20?
13 · 20 · Complements to 10, 20 & 100
3. How many more do you need to add to 44 to make 50?
44 · 50 · Complements to 10, 20 & 100
4. How many more do you need to add to 29 to make 30?
29 · 30 · Complements to 10, 20 & 100
5. How many more do you need to add to 14 to make 30?
14 · 30 · 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 1 to make 50?
1 · 50 · Complements to 10, 20 & 100
8. How many more do you need to add to 22 to make 30?
22 · 30 · Complements to 10, 20 & 100
9. How many more do you need to add to 6 to make 100?
6 · 100 · Complements to 10, 20 & 100
10. How many more do you need to add to 11 to make 30?
11 · 30 · Complements to 10, 20 & 100
11. How many more do you need to add to 7 to make 30?
7 · 30 · Complements to 10, 20 & 100
12. How many more do you need to add to 1 to make 100?
1 · 100 · Complements to 10, 20 & 100

12 questions · Seed 104780 · 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 33 to make 50?
17
Subtract 33 from 50: 50 − 33 = 17.
2. How many more do you need to add to 13 to make 20?
7
Subtract 13 from 20: 20 − 13 = 7.
3. How many more do you need to add to 44 to make 50?
6
Subtract 44 from 50: 50 − 44 = 6.
4. How many more do you need to add to 29 to make 30?
1
Subtract 29 from 30: 30 − 29 = 1.
5. How many more do you need to add to 14 to make 30?
16
Subtract 14 from 30: 30 − 14 = 16.
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 1 to make 50?
49
Subtract 1 from 50: 50 − 1 = 49.
8. How many more do you need to add to 22 to make 30?
8
Subtract 22 from 30: 30 − 22 = 8.
9. How many more do you need to add to 6 to make 100?
94
Subtract 6 from 100: 100 − 6 = 94.
10. How many more do you need to add to 11 to make 30?
19
Subtract 11 from 30: 30 − 11 = 19.
11. How many more do you need to add to 7 to make 30?
23
Subtract 7 from 30: 30 − 7 = 23.
12. How many more do you need to add to 1 to make 100?
99
Subtract 1 from 100: 100 − 1 = 99.

12 questions · Seed 104780 · 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 33 to make 50?
33 · 50 · Complements to 10, 20 & 100
2. How many more do you need to add to 13 to make 20?
13 · 20 · Complements to 10, 20 & 100
3. How many more do you need to add to 44 to make 50?
44 · 50 · Complements to 10, 20 & 100
4. How many more do you need to add to 29 to make 30?
29 · 30 · Complements to 10, 20 & 100
5. How many more do you need to add to 14 to make 30?
14 · 30 · 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 1 to make 50?
1 · 50 · Complements to 10, 20 & 100
8. How many more do you need to add to 22 to make 30?
22 · 30 · Complements to 10, 20 & 100
9. How many more do you need to add to 6 to make 100?
6 · 100 · Complements to 10, 20 & 100
10. How many more do you need to add to 11 to make 30?
11 · 30 · Complements to 10, 20 & 100
11. How many more do you need to add to 7 to make 30?
7 · 30 · Complements to 10, 20 & 100
12. How many more do you need to add to 1 to make 100?
1 · 100 · Complements to 10, 20 & 100

12 questions · Seed 104780 · 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 33 to make 50?
17
Subtract 33 from 50: 50 − 33 = 17.
2. How many more do you need to add to 13 to make 20?
7
Subtract 13 from 20: 20 − 13 = 7.
3. How many more do you need to add to 44 to make 50?
6
Subtract 44 from 50: 50 − 44 = 6.
4. How many more do you need to add to 29 to make 30?
1
Subtract 29 from 30: 30 − 29 = 1.
5. How many more do you need to add to 14 to make 30?
16
Subtract 14 from 30: 30 − 14 = 16.
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 1 to make 50?
49
Subtract 1 from 50: 50 − 1 = 49.
8. How many more do you need to add to 22 to make 30?
8
Subtract 22 from 30: 30 − 22 = 8.
9. How many more do you need to add to 6 to make 100?
94
Subtract 6 from 100: 100 − 6 = 94.
10. How many more do you need to add to 11 to make 30?
19
Subtract 11 from 30: 30 − 11 = 19.
11. How many more do you need to add to 7 to make 30?
23
Subtract 7 from 30: 30 − 7 = 23.
12. How many more do you need to add to 1 to make 100?
99
Subtract 1 from 100: 100 − 1 = 99.

12 questions · Seed 104780 · Age guidance, not curriculum certification