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 5 to make 30?
5 · 30 · Complements to 10, 20 & 100
2. How many more do you need to add to 86 to make 100?
86 · 100 · Complements to 10, 20 & 100
3. How many more do you need to add to 81 to make 100?
81 · 100 · Complements to 10, 20 & 100
4. How many more do you need to add to 14 to make 20?
14 · 20 · Complements to 10, 20 & 100
5. How many more do you need to add to 26 to make 50?
26 · 50 · Complements to 10, 20 & 100
6. How many more do you need to add to 10 to make 50?
10 · 50 · Complements to 10, 20 & 100
7. How many more do you need to add to 99 to make 100?
99 · 100 · Complements to 10, 20 & 100
8. How many more do you need to add to 42 to make 50?
42 · 50 · Complements to 10, 20 & 100
9. How many more do you need to add to 8 to make 30?
8 · 30 · Complements to 10, 20 & 100
10. How many more do you need to add to 14 to make 50?
14 · 50 · Complements to 10, 20 & 100
11. How many more do you need to add to 48 to make 50?
48 · 50 · Complements to 10, 20 & 100
12. How many more do you need to add to 10 to make 30?
10 · 30 · Complements to 10, 20 & 100

12 questions · Seed 104761 · 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 5 to make 30?
25
Subtract 5 from 30: 30 − 5 = 25.
2. How many more do you need to add to 86 to make 100?
14
Subtract 86 from 100: 100 − 86 = 14.
3. How many more do you need to add to 81 to make 100?
19
Subtract 81 from 100: 100 − 81 = 19.
4. How many more do you need to add to 14 to make 20?
6
Subtract 14 from 20: 20 − 14 = 6.
5. How many more do you need to add to 26 to make 50?
24
Subtract 26 from 50: 50 − 26 = 24.
6. How many more do you need to add to 10 to make 50?
40
Subtract 10 from 50: 50 − 10 = 40.
7. How many more do you need to add to 99 to make 100?
1
Subtract 99 from 100: 100 − 99 = 1.
8. How many more do you need to add to 42 to make 50?
8
Subtract 42 from 50: 50 − 42 = 8.
9. How many more do you need to add to 8 to make 30?
22
Subtract 8 from 30: 30 − 8 = 22.
10. How many more do you need to add to 14 to make 50?
36
Subtract 14 from 50: 50 − 14 = 36.
11. How many more do you need to add to 48 to make 50?
2
Subtract 48 from 50: 50 − 48 = 2.
12. How many more do you need to add to 10 to make 30?
20
Subtract 10 from 30: 30 − 10 = 20.

12 questions · Seed 104761 · 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 5 to make 30?
5 · 30 · Complements to 10, 20 & 100
2. How many more do you need to add to 86 to make 100?
86 · 100 · Complements to 10, 20 & 100
3. How many more do you need to add to 81 to make 100?
81 · 100 · Complements to 10, 20 & 100
4. How many more do you need to add to 14 to make 20?
14 · 20 · Complements to 10, 20 & 100
5. How many more do you need to add to 26 to make 50?
26 · 50 · Complements to 10, 20 & 100
6. How many more do you need to add to 10 to make 50?
10 · 50 · Complements to 10, 20 & 100
7. How many more do you need to add to 99 to make 100?
99 · 100 · Complements to 10, 20 & 100
8. How many more do you need to add to 42 to make 50?
42 · 50 · Complements to 10, 20 & 100
9. How many more do you need to add to 8 to make 30?
8 · 30 · Complements to 10, 20 & 100
10. How many more do you need to add to 14 to make 50?
14 · 50 · Complements to 10, 20 & 100
11. How many more do you need to add to 48 to make 50?
48 · 50 · Complements to 10, 20 & 100
12. How many more do you need to add to 10 to make 30?
10 · 30 · Complements to 10, 20 & 100

12 questions · Seed 104761 · 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 5 to make 30?
25
Subtract 5 from 30: 30 − 5 = 25.
2. How many more do you need to add to 86 to make 100?
14
Subtract 86 from 100: 100 − 86 = 14.
3. How many more do you need to add to 81 to make 100?
19
Subtract 81 from 100: 100 − 81 = 19.
4. How many more do you need to add to 14 to make 20?
6
Subtract 14 from 20: 20 − 14 = 6.
5. How many more do you need to add to 26 to make 50?
24
Subtract 26 from 50: 50 − 26 = 24.
6. How many more do you need to add to 10 to make 50?
40
Subtract 10 from 50: 50 − 10 = 40.
7. How many more do you need to add to 99 to make 100?
1
Subtract 99 from 100: 100 − 99 = 1.
8. How many more do you need to add to 42 to make 50?
8
Subtract 42 from 50: 50 − 42 = 8.
9. How many more do you need to add to 8 to make 30?
22
Subtract 8 from 30: 30 − 8 = 22.
10. How many more do you need to add to 14 to make 50?
36
Subtract 14 from 50: 50 − 14 = 36.
11. How many more do you need to add to 48 to make 50?
2
Subtract 48 from 50: 50 − 48 = 2.
12. How many more do you need to add to 10 to make 30?
20
Subtract 10 from 30: 30 − 10 = 20.

12 questions · Seed 104761 · Age guidance, not curriculum certification