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 73 · 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: 20, 23, ____, 29, 32.
26
The sequence increases by 3 each step: 23 + 3 = 26.
2. Find the missing number in the sequence: 9, 15, ____, 27, 33.
21
The sequence increases by 6 each step: 15 + 6 = 21.
3. Find the missing number in the sequence: 5, 14, ____, 32, 41.
23
The sequence increases by 9 each step: 14 + 9 = 23.
4. Find the missing number in the sequence: 14, 17, ____, 23, 26.
20
The sequence increases by 3 each step: 17 + 3 = 20.
5. Find the missing number in the sequence: 3, 10, ____, 24, 31.
17
The sequence increases by 7 each step: 10 + 7 = 17.
6. Find the missing number in the sequence: 7, 14, ____, 28, 35.
21
The sequence increases by 7 each step: 14 + 7 = 21.
7. Find the missing number in the sequence: 7, 11, ____, 19, 23.
15
The sequence increases by 4 each step: 11 + 4 = 15.
8. Find the missing number in the sequence: 19, 27, ____, 43, 51.
35
The sequence increases by 8 each step: 27 + 8 = 35.
9. Find the missing number in the sequence: 1, 5, ____, 13, 17.
9
The sequence increases by 4 each step: 5 + 4 = 9.
10. Find the missing number in the sequence: 14, 20, ____, 32, 38.
26
The sequence increases by 6 each step: 20 + 6 = 26.
11. Find the missing number in the sequence: 15, 18, ____, 24, 27.
21
The sequence increases by 3 each step: 18 + 3 = 21.
12. Find the missing number in the sequence: 15, 19, ____, 27, 31.
23
The sequence increases by 4 each step: 19 + 4 = 23.

12 questions · Seed 73 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 7-9

Take your time. Show your thinking.

12 questions · Seed 73 · 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: 20, 23, ____, 29, 32.
26
The sequence increases by 3 each step: 23 + 3 = 26.
2. Find the missing number in the sequence: 9, 15, ____, 27, 33.
21
The sequence increases by 6 each step: 15 + 6 = 21.
3. Find the missing number in the sequence: 5, 14, ____, 32, 41.
23
The sequence increases by 9 each step: 14 + 9 = 23.
4. Find the missing number in the sequence: 14, 17, ____, 23, 26.
20
The sequence increases by 3 each step: 17 + 3 = 20.
5. Find the missing number in the sequence: 3, 10, ____, 24, 31.
17
The sequence increases by 7 each step: 10 + 7 = 17.
6. Find the missing number in the sequence: 7, 14, ____, 28, 35.
21
The sequence increases by 7 each step: 14 + 7 = 21.
7. Find the missing number in the sequence: 7, 11, ____, 19, 23.
15
The sequence increases by 4 each step: 11 + 4 = 15.
8. Find the missing number in the sequence: 19, 27, ____, 43, 51.
35
The sequence increases by 8 each step: 27 + 8 = 35.
9. Find the missing number in the sequence: 1, 5, ____, 13, 17.
9
The sequence increases by 4 each step: 5 + 4 = 9.
10. Find the missing number in the sequence: 14, 20, ____, 32, 38.
26
The sequence increases by 6 each step: 20 + 6 = 26.
11. Find the missing number in the sequence: 15, 18, ____, 24, 27.
21
The sequence increases by 3 each step: 18 + 3 = 21.
12. Find the missing number in the sequence: 15, 19, ____, 27, 31.
23
The sequence increases by 4 each step: 19 + 4 = 23.

12 questions · Seed 73 · Age guidance, not curriculum certification