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 74 · 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: 5, 9, ____, 17, 21.
13
The sequence increases by 4 each step: 9 + 4 = 13.
2. Find the missing number in the sequence: 15, 18, ____, 24, 27.
21
The sequence increases by 3 each step: 18 + 3 = 21.
3. Find the missing number in the sequence: 15, 23, ____, 39, 47.
31
The sequence increases by 8 each step: 23 + 8 = 31.
4. Find the missing number in the sequence: 11, 19, ____, 35, 43.
27
The sequence increases by 8 each step: 19 + 8 = 27.
5. Find the missing number in the sequence: 5, 15, ____, 35, 45.
25
The sequence increases by 10 each step: 15 + 10 = 25.
6. Find the missing number in the sequence: 4, 7, ____, 13, 16.
10
The sequence increases by 3 each step: 7 + 3 = 10.
7. Find the missing number in the sequence: 12, 16, ____, 24, 28.
20
The sequence increases by 4 each step: 16 + 4 = 20.
8. Find the missing number in the sequence: 10, 20, ____, 40, 50.
30
The sequence increases by 10 each step: 20 + 10 = 30.
9. Find the missing number in the sequence: 5, 14, ____, 32, 41.
23
The sequence increases by 9 each step: 14 + 9 = 23.
10. Find the missing number in the sequence: 15, 22, ____, 36, 43.
29
The sequence increases by 7 each step: 22 + 7 = 29.
11. Find the missing number in the sequence: 4, 10, ____, 22, 28.
16
The sequence increases by 6 each step: 10 + 6 = 16.
12. Find the missing number in the sequence: 7, 15, ____, 31, 39.
23
The sequence increases by 8 each step: 15 + 8 = 23.

12 questions · Seed 74 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 7-9

Take your time. Show your thinking.

12 questions · Seed 74 · 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: 5, 9, ____, 17, 21.
13
The sequence increases by 4 each step: 9 + 4 = 13.
2. Find the missing number in the sequence: 15, 18, ____, 24, 27.
21
The sequence increases by 3 each step: 18 + 3 = 21.
3. Find the missing number in the sequence: 15, 23, ____, 39, 47.
31
The sequence increases by 8 each step: 23 + 8 = 31.
4. Find the missing number in the sequence: 11, 19, ____, 35, 43.
27
The sequence increases by 8 each step: 19 + 8 = 27.
5. Find the missing number in the sequence: 5, 15, ____, 35, 45.
25
The sequence increases by 10 each step: 15 + 10 = 25.
6. Find the missing number in the sequence: 4, 7, ____, 13, 16.
10
The sequence increases by 3 each step: 7 + 3 = 10.
7. Find the missing number in the sequence: 12, 16, ____, 24, 28.
20
The sequence increases by 4 each step: 16 + 4 = 20.
8. Find the missing number in the sequence: 10, 20, ____, 40, 50.
30
The sequence increases by 10 each step: 20 + 10 = 30.
9. Find the missing number in the sequence: 5, 14, ____, 32, 41.
23
The sequence increases by 9 each step: 14 + 9 = 23.
10. Find the missing number in the sequence: 15, 22, ____, 36, 43.
29
The sequence increases by 7 each step: 22 + 7 = 29.
11. Find the missing number in the sequence: 4, 10, ____, 22, 28.
16
The sequence increases by 6 each step: 10 + 6 = 16.
12. Find the missing number in the sequence: 7, 15, ____, 31, 39.
23
The sequence increases by 8 each step: 15 + 8 = 23.

12 questions · Seed 74 · Age guidance, not curriculum certification