ReasoningAges 7-9

Missing sequence terms

Use the constant step size between terms to find the missing middle number in a sequence. Review suitability for your learners before teaching.

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Worksheet StudioPractice pack · Ages 7-9

Take your time. Show your thinking.

12 questions · Seed 86 · Age guidance, not curriculum certification

View the answer key

Worksheet StudioAnswer key · Ages 7-9

Answers and reasoning. Review before teaching.

1. Find the missing number in the sequence: 7, 13, ____, 25, 31.
19
The sequence increases by 6 each step: 13 + 6 = 19.
2. Find the missing number in the sequence: 4, 8, ____, 16, 20.
12
The sequence increases by 4 each step: 8 + 4 = 12.
3. Find the missing number in the sequence: 12, 21, ____, 39, 48.
30
The sequence increases by 9 each step: 21 + 9 = 30.
4. Find the missing number in the sequence: 3, 6, ____, 12, 15.
9
The sequence increases by 3 each step: 6 + 3 = 9.
5. Find the missing number in the sequence: 20, 27, ____, 41, 48.
34
The sequence increases by 7 each step: 27 + 7 = 34.
6. Find the missing number in the sequence: 1, 11, ____, 31, 41.
21
The sequence increases by 10 each step: 11 + 10 = 21.
7. Find the missing number in the sequence: 9, 15, ____, 27, 33.
21
The sequence increases by 6 each step: 15 + 6 = 21.
8. Find the missing number in the sequence: 7, 15, ____, 31, 39.
23
The sequence increases by 8 each step: 15 + 8 = 23.
9. Find the missing number in the sequence: 10, 20, ____, 40, 50.
30
The sequence increases by 10 each step: 20 + 10 = 30.
10. Find the missing number in the sequence: 20, 24, ____, 32, 36.
28
The sequence increases by 4 each step: 24 + 4 = 28.
11. Find the missing number in the sequence: 14, 23, ____, 41, 50.
32
The sequence increases by 9 each step: 23 + 9 = 32.
12. Find the missing number in the sequence: 6, 16, ____, 36, 46.
26
The sequence increases by 10 each step: 16 + 10 = 26.

12 questions · Seed 86 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 7-9

Take your time. Show your thinking.

12 questions · Seed 86 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 7-9

Answers and reasoning. Review before teaching.

1. Find the missing number in the sequence: 7, 13, ____, 25, 31.
19
The sequence increases by 6 each step: 13 + 6 = 19.
2. Find the missing number in the sequence: 4, 8, ____, 16, 20.
12
The sequence increases by 4 each step: 8 + 4 = 12.
3. Find the missing number in the sequence: 12, 21, ____, 39, 48.
30
The sequence increases by 9 each step: 21 + 9 = 30.
4. Find the missing number in the sequence: 3, 6, ____, 12, 15.
9
The sequence increases by 3 each step: 6 + 3 = 9.
5. Find the missing number in the sequence: 20, 27, ____, 41, 48.
34
The sequence increases by 7 each step: 27 + 7 = 34.
6. Find the missing number in the sequence: 1, 11, ____, 31, 41.
21
The sequence increases by 10 each step: 11 + 10 = 21.
7. Find the missing number in the sequence: 9, 15, ____, 27, 33.
21
The sequence increases by 6 each step: 15 + 6 = 21.
8. Find the missing number in the sequence: 7, 15, ____, 31, 39.
23
The sequence increases by 8 each step: 15 + 8 = 23.
9. Find the missing number in the sequence: 10, 20, ____, 40, 50.
30
The sequence increases by 10 each step: 20 + 10 = 30.
10. Find the missing number in the sequence: 20, 24, ____, 32, 36.
28
The sequence increases by 4 each step: 24 + 4 = 28.
11. Find the missing number in the sequence: 14, 23, ____, 41, 50.
32
The sequence increases by 9 each step: 23 + 9 = 32.
12. Find the missing number in the sequence: 6, 16, ____, 36, 46.
26
The sequence increases by 10 each step: 16 + 10 = 26.

12 questions · Seed 86 · Age guidance, not curriculum certification