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 79 · 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, 24, ____, 32, 36.
28
The sequence increases by 4 each step: 24 + 4 = 28.
2. Find the missing number in the sequence: 11, 17, ____, 29, 35.
23
The sequence increases by 6 each step: 17 + 6 = 23.
3. Find the missing number in the sequence: 9, 13, ____, 21, 25.
17
The sequence increases by 4 each step: 13 + 4 = 17.
4. Find the missing number in the sequence: 15, 21, ____, 33, 39.
27
The sequence increases by 6 each step: 21 + 6 = 27.
5. Find the missing number in the sequence: 4, 11, ____, 25, 32.
18
The sequence increases by 7 each step: 11 + 7 = 18.
6. Find the missing number in the sequence: 14, 17, ____, 23, 26.
20
The sequence increases by 3 each step: 17 + 3 = 20.
7. Find the missing number in the sequence: 11, 21, ____, 41, 51.
31
The sequence increases by 10 each step: 21 + 10 = 31.
8. Find the missing number in the sequence: 6, 15, ____, 33, 42.
24
The sequence increases by 9 each step: 15 + 9 = 24.
9. Find the missing number in the sequence: 2, 10, ____, 26, 34.
18
The sequence increases by 8 each step: 10 + 8 = 18.
10. Find the missing number in the sequence: 15, 23, ____, 39, 47.
31
The sequence increases by 8 each step: 23 + 8 = 31.
11. Find the missing number in the sequence: 13, 16, ____, 22, 25.
19
The sequence increases by 3 each step: 16 + 3 = 19.
12. Find the missing number in the sequence: 12, 18, ____, 30, 36.
24
The sequence increases by 6 each step: 18 + 6 = 24.

12 questions · Seed 79 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 7-9

Take your time. Show your thinking.

12 questions · Seed 79 · 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, 24, ____, 32, 36.
28
The sequence increases by 4 each step: 24 + 4 = 28.
2. Find the missing number in the sequence: 11, 17, ____, 29, 35.
23
The sequence increases by 6 each step: 17 + 6 = 23.
3. Find the missing number in the sequence: 9, 13, ____, 21, 25.
17
The sequence increases by 4 each step: 13 + 4 = 17.
4. Find the missing number in the sequence: 15, 21, ____, 33, 39.
27
The sequence increases by 6 each step: 21 + 6 = 27.
5. Find the missing number in the sequence: 4, 11, ____, 25, 32.
18
The sequence increases by 7 each step: 11 + 7 = 18.
6. Find the missing number in the sequence: 14, 17, ____, 23, 26.
20
The sequence increases by 3 each step: 17 + 3 = 20.
7. Find the missing number in the sequence: 11, 21, ____, 41, 51.
31
The sequence increases by 10 each step: 21 + 10 = 31.
8. Find the missing number in the sequence: 6, 15, ____, 33, 42.
24
The sequence increases by 9 each step: 15 + 9 = 24.
9. Find the missing number in the sequence: 2, 10, ____, 26, 34.
18
The sequence increases by 8 each step: 10 + 8 = 18.
10. Find the missing number in the sequence: 15, 23, ____, 39, 47.
31
The sequence increases by 8 each step: 23 + 8 = 31.
11. Find the missing number in the sequence: 13, 16, ____, 22, 25.
19
The sequence increases by 3 each step: 16 + 3 = 19.
12. Find the missing number in the sequence: 12, 18, ____, 30, 36.
24
The sequence increases by 6 each step: 18 + 6 = 24.

12 questions · Seed 79 · Age guidance, not curriculum certification