MathsAges 4-6

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 4-6

Take your time. Show your thinking.

1. How many more do you need to add to 2 to make 12?
2 · 12 · Complements to 10, 20 & 100
2. How many more do you need to add to 17 to make 20?
17 · 20 · Complements to 10, 20 & 100
3. How many more do you need to add to 16 to make 20?
16 · 20 · Complements to 10, 20 & 100
4. How many more do you need to add to 7 to make 10?
7 · 10 · Complements to 10, 20 & 100
5. How many more do you need to add to 8 to make 15?
8 · 15 · Complements to 10, 20 & 100
6. How many more do you need to add to 3 to make 15?
3 · 15 · Complements to 10, 20 & 100
7. How many more do you need to add to 19 to make 20?
19 · 20 · Complements to 10, 20 & 100
8. How many more do you need to add to 12 to make 15?
12 · 15 · Complements to 10, 20 & 100
9. How many more do you need to add to 3 to make 12?
3 · 12 · Complements to 10, 20 & 100
10. How many more do you need to add to 4 to make 15?
4 · 15 · Complements to 10, 20 & 100
11. How many more do you need to add to 14 to make 15?
14 · 15 · Complements to 10, 20 & 100
12. How many more do you need to add to 4 to make 12?
4 · 12 · Complements to 10, 20 & 100

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

View the answer key

Worksheet StudioAnswer key · Ages 4-6

Answers and reasoning. Review before teaching.

1. How many more do you need to add to 2 to make 12?
10
Subtract 2 from 12: 12 − 2 = 10.
2. How many more do you need to add to 17 to make 20?
3
Subtract 17 from 20: 20 − 17 = 3.
3. How many more do you need to add to 16 to make 20?
4
Subtract 16 from 20: 20 − 16 = 4.
4. How many more do you need to add to 7 to make 10?
3
Subtract 7 from 10: 10 − 7 = 3.
5. How many more do you need to add to 8 to make 15?
7
Subtract 8 from 15: 15 − 8 = 7.
6. How many more do you need to add to 3 to make 15?
12
Subtract 3 from 15: 15 − 3 = 12.
7. How many more do you need to add to 19 to make 20?
1
Subtract 19 from 20: 20 − 19 = 1.
8. How many more do you need to add to 12 to make 15?
3
Subtract 12 from 15: 15 − 12 = 3.
9. How many more do you need to add to 3 to make 12?
9
Subtract 3 from 12: 12 − 3 = 9.
10. How many more do you need to add to 4 to make 15?
11
Subtract 4 from 15: 15 − 4 = 11.
11. How many more do you need to add to 14 to make 15?
1
Subtract 14 from 15: 15 − 14 = 1.
12. How many more do you need to add to 4 to make 12?
8
Subtract 4 from 12: 12 − 4 = 8.

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

Worksheet StudioPractice pack · Ages 4-6

Take your time. Show your thinking.

1. How many more do you need to add to 2 to make 12?
2 · 12 · Complements to 10, 20 & 100
2. How many more do you need to add to 17 to make 20?
17 · 20 · Complements to 10, 20 & 100
3. How many more do you need to add to 16 to make 20?
16 · 20 · Complements to 10, 20 & 100
4. How many more do you need to add to 7 to make 10?
7 · 10 · Complements to 10, 20 & 100
5. How many more do you need to add to 8 to make 15?
8 · 15 · Complements to 10, 20 & 100
6. How many more do you need to add to 3 to make 15?
3 · 15 · Complements to 10, 20 & 100
7. How many more do you need to add to 19 to make 20?
19 · 20 · Complements to 10, 20 & 100
8. How many more do you need to add to 12 to make 15?
12 · 15 · Complements to 10, 20 & 100
9. How many more do you need to add to 3 to make 12?
3 · 12 · Complements to 10, 20 & 100
10. How many more do you need to add to 4 to make 15?
4 · 15 · Complements to 10, 20 & 100
11. How many more do you need to add to 14 to make 15?
14 · 15 · Complements to 10, 20 & 100
12. How many more do you need to add to 4 to make 12?
4 · 12 · Complements to 10, 20 & 100

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

Worksheet StudioAnswer key · Ages 4-6

Answers and reasoning. Review before teaching.

1. How many more do you need to add to 2 to make 12?
10
Subtract 2 from 12: 12 − 2 = 10.
2. How many more do you need to add to 17 to make 20?
3
Subtract 17 from 20: 20 − 17 = 3.
3. How many more do you need to add to 16 to make 20?
4
Subtract 16 from 20: 20 − 16 = 4.
4. How many more do you need to add to 7 to make 10?
3
Subtract 7 from 10: 10 − 7 = 3.
5. How many more do you need to add to 8 to make 15?
7
Subtract 8 from 15: 15 − 8 = 7.
6. How many more do you need to add to 3 to make 15?
12
Subtract 3 from 15: 15 − 3 = 12.
7. How many more do you need to add to 19 to make 20?
1
Subtract 19 from 20: 20 − 19 = 1.
8. How many more do you need to add to 12 to make 15?
3
Subtract 12 from 15: 15 − 12 = 3.
9. How many more do you need to add to 3 to make 12?
9
Subtract 3 from 12: 12 − 3 = 9.
10. How many more do you need to add to 4 to make 15?
11
Subtract 4 from 15: 15 − 4 = 11.
11. How many more do you need to add to 14 to make 15?
1
Subtract 14 from 15: 15 − 14 = 1.
12. How many more do you need to add to 4 to make 12?
8
Subtract 4 from 12: 12 − 4 = 8.

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