ReasoningAges 4-6

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 4-6

Take your time. Show your thinking.

12 questions · Seed 80 · Age guidance, not curriculum certification

View the answer key

Worksheet StudioAnswer key · Ages 4-6

Answers and reasoning. Review before teaching.

1. Find the missing number in the sequence: 17, 19, ____, 23, 25.
21
The sequence increases by 2 each step: 19 + 2 = 21.
2. Find the missing number in the sequence: 16, 21, ____, 31, 36.
26
The sequence increases by 5 each step: 21 + 5 = 26.
3. Find the missing number in the sequence: 1, 2, ____, 4, 5.
3
The sequence increases by 1 each step: 2 + 1 = 3.
4. Find the missing number in the sequence: 14, 15, ____, 17, 18.
16
The sequence increases by 1 each step: 15 + 1 = 16.
5. Find the missing number in the sequence: 13, 18, ____, 28, 33.
23
The sequence increases by 5 each step: 18 + 5 = 23.
6. Find the missing number in the sequence: 15, 20, ____, 30, 35.
25
The sequence increases by 5 each step: 20 + 5 = 25.
7. Find the missing number in the sequence: 8, 13, ____, 23, 28.
18
The sequence increases by 5 each step: 13 + 5 = 18.
8. Find the missing number in the sequence: 19, 20, ____, 22, 23.
21
The sequence increases by 1 each step: 20 + 1 = 21.
9. Find the missing number in the sequence: 12, 14, ____, 18, 20.
16
The sequence increases by 2 each step: 14 + 2 = 16.
10. Find the missing number in the sequence: 11, 16, ____, 26, 31.
21
The sequence increases by 5 each step: 16 + 5 = 21.
11. Find the missing number in the sequence: 18, 20, ____, 24, 26.
22
The sequence increases by 2 each step: 20 + 2 = 22.
12. Find the missing number in the sequence: 13, 14, ____, 16, 17.
15
The sequence increases by 1 each step: 14 + 1 = 15.

12 questions · Seed 80 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 4-6

Take your time. Show your thinking.

12 questions · Seed 80 · Age guidance, not curriculum certification

Worksheet StudioAnswer key · Ages 4-6

Answers and reasoning. Review before teaching.

1. Find the missing number in the sequence: 17, 19, ____, 23, 25.
21
The sequence increases by 2 each step: 19 + 2 = 21.
2. Find the missing number in the sequence: 16, 21, ____, 31, 36.
26
The sequence increases by 5 each step: 21 + 5 = 26.
3. Find the missing number in the sequence: 1, 2, ____, 4, 5.
3
The sequence increases by 1 each step: 2 + 1 = 3.
4. Find the missing number in the sequence: 14, 15, ____, 17, 18.
16
The sequence increases by 1 each step: 15 + 1 = 16.
5. Find the missing number in the sequence: 13, 18, ____, 28, 33.
23
The sequence increases by 5 each step: 18 + 5 = 23.
6. Find the missing number in the sequence: 15, 20, ____, 30, 35.
25
The sequence increases by 5 each step: 20 + 5 = 25.
7. Find the missing number in the sequence: 8, 13, ____, 23, 28.
18
The sequence increases by 5 each step: 13 + 5 = 18.
8. Find the missing number in the sequence: 19, 20, ____, 22, 23.
21
The sequence increases by 1 each step: 20 + 1 = 21.
9. Find the missing number in the sequence: 12, 14, ____, 18, 20.
16
The sequence increases by 2 each step: 14 + 2 = 16.
10. Find the missing number in the sequence: 11, 16, ____, 26, 31.
21
The sequence increases by 5 each step: 16 + 5 = 21.
11. Find the missing number in the sequence: 18, 20, ____, 24, 26.
22
The sequence increases by 2 each step: 20 + 2 = 22.
12. Find the missing number in the sequence: 13, 14, ____, 16, 17.
15
The sequence increases by 1 each step: 14 + 1 = 15.

12 questions · Seed 80 · Age guidance, not curriculum certification