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 99 · 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: 11, 17, ____, 29, 35.
23
The sequence increases by 6 each step: 17 + 6 = 23.
2. Find the missing number in the sequence: 12, 22, ____, 42, 52.
32
The sequence increases by 10 each step: 22 + 10 = 32.
3. Find the missing number in the sequence: 8, 14, ____, 26, 32.
20
The sequence increases by 6 each step: 14 + 6 = 20.
4. Find the missing number in the sequence: 17, 20, ____, 26, 29.
23
The sequence increases by 3 each step: 20 + 3 = 23.
5. Find the missing number in the sequence: 2, 11, ____, 29, 38.
20
The sequence increases by 9 each step: 11 + 9 = 20.
6. Find the missing number in the sequence: 16, 24, ____, 40, 48.
32
The sequence increases by 8 each step: 24 + 8 = 32.
7. Find the missing number in the sequence: 5, 13, ____, 29, 37.
21
The sequence increases by 8 each step: 13 + 8 = 21.
8. Find the missing number in the sequence: 12, 19, ____, 33, 40.
26
The sequence increases by 7 each step: 19 + 7 = 26.
9. Find the missing number in the sequence: 13, 21, ____, 37, 45.
29
The sequence increases by 8 each step: 21 + 8 = 29.
10. Find the missing number in the sequence: 11, 21, ____, 41, 51.
31
The sequence increases by 10 each step: 21 + 10 = 31.
11. Find the missing number in the sequence: 18, 22, ____, 30, 34.
26
The sequence increases by 4 each step: 22 + 4 = 26.
12. Find the missing number in the sequence: 11, 15, ____, 23, 27.
19
The sequence increases by 4 each step: 15 + 4 = 19.

12 questions · Seed 99 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 7-9

Take your time. Show your thinking.

12 questions · Seed 99 · 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: 11, 17, ____, 29, 35.
23
The sequence increases by 6 each step: 17 + 6 = 23.
2. Find the missing number in the sequence: 12, 22, ____, 42, 52.
32
The sequence increases by 10 each step: 22 + 10 = 32.
3. Find the missing number in the sequence: 8, 14, ____, 26, 32.
20
The sequence increases by 6 each step: 14 + 6 = 20.
4. Find the missing number in the sequence: 17, 20, ____, 26, 29.
23
The sequence increases by 3 each step: 20 + 3 = 23.
5. Find the missing number in the sequence: 2, 11, ____, 29, 38.
20
The sequence increases by 9 each step: 11 + 9 = 20.
6. Find the missing number in the sequence: 16, 24, ____, 40, 48.
32
The sequence increases by 8 each step: 24 + 8 = 32.
7. Find the missing number in the sequence: 5, 13, ____, 29, 37.
21
The sequence increases by 8 each step: 13 + 8 = 21.
8. Find the missing number in the sequence: 12, 19, ____, 33, 40.
26
The sequence increases by 7 each step: 19 + 7 = 26.
9. Find the missing number in the sequence: 13, 21, ____, 37, 45.
29
The sequence increases by 8 each step: 21 + 8 = 29.
10. Find the missing number in the sequence: 11, 21, ____, 41, 51.
31
The sequence increases by 10 each step: 21 + 10 = 31.
11. Find the missing number in the sequence: 18, 22, ____, 30, 34.
26
The sequence increases by 4 each step: 22 + 4 = 26.
12. Find the missing number in the sequence: 11, 15, ____, 23, 27.
19
The sequence increases by 4 each step: 15 + 4 = 19.

12 questions · Seed 99 · Age guidance, not curriculum certification