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 103 · 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: 19, 20, ____, 22, 23.
21
The sequence increases by 1 each step: 20 + 1 = 21.
2. Find the missing number in the sequence: 7, 9, ____, 13, 15.
11
The sequence increases by 2 each step: 9 + 2 = 11.
3. Find the missing number in the sequence: 11, 12, ____, 14, 15.
13
The sequence increases by 1 each step: 12 + 1 = 13.
4. Find the missing number in the sequence: 7, 12, ____, 22, 27.
17
The sequence increases by 5 each step: 12 + 5 = 17.
5. Find the missing number in the sequence: 5, 6, ____, 8, 9.
7
The sequence increases by 1 each step: 6 + 1 = 7.
6. Find the missing number in the sequence: 13, 18, ____, 28, 33.
23
The sequence increases by 5 each step: 18 + 5 = 23.
7. Find the missing number in the sequence: 13, 15, ____, 19, 21.
17
The sequence increases by 2 each step: 15 + 2 = 17.
8. Find the missing number in the sequence: 20, 22, ____, 26, 28.
24
The sequence increases by 2 each step: 22 + 2 = 24.
9. Find the missing number in the sequence: 9, 11, ____, 15, 17.
13
The sequence increases by 2 each step: 11 + 2 = 13.
10. Find the missing number in the sequence: 5, 7, ____, 11, 13.
9
The sequence increases by 2 each step: 7 + 2 = 9.
11. Find the missing number in the sequence: 9, 10, ____, 12, 13.
11
The sequence increases by 1 each step: 10 + 1 = 11.
12. Find the missing number in the sequence: 6, 8, ____, 12, 14.
10
The sequence increases by 2 each step: 8 + 2 = 10.

12 questions · Seed 103 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 4-6

Take your time. Show your thinking.

12 questions · Seed 103 · 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: 19, 20, ____, 22, 23.
21
The sequence increases by 1 each step: 20 + 1 = 21.
2. Find the missing number in the sequence: 7, 9, ____, 13, 15.
11
The sequence increases by 2 each step: 9 + 2 = 11.
3. Find the missing number in the sequence: 11, 12, ____, 14, 15.
13
The sequence increases by 1 each step: 12 + 1 = 13.
4. Find the missing number in the sequence: 7, 12, ____, 22, 27.
17
The sequence increases by 5 each step: 12 + 5 = 17.
5. Find the missing number in the sequence: 5, 6, ____, 8, 9.
7
The sequence increases by 1 each step: 6 + 1 = 7.
6. Find the missing number in the sequence: 13, 18, ____, 28, 33.
23
The sequence increases by 5 each step: 18 + 5 = 23.
7. Find the missing number in the sequence: 13, 15, ____, 19, 21.
17
The sequence increases by 2 each step: 15 + 2 = 17.
8. Find the missing number in the sequence: 20, 22, ____, 26, 28.
24
The sequence increases by 2 each step: 22 + 2 = 24.
9. Find the missing number in the sequence: 9, 11, ____, 15, 17.
13
The sequence increases by 2 each step: 11 + 2 = 13.
10. Find the missing number in the sequence: 5, 7, ____, 11, 13.
9
The sequence increases by 2 each step: 7 + 2 = 9.
11. Find the missing number in the sequence: 9, 10, ____, 12, 13.
11
The sequence increases by 1 each step: 10 + 1 = 11.
12. Find the missing number in the sequence: 6, 8, ____, 12, 14.
10
The sequence increases by 2 each step: 8 + 2 = 10.

12 questions · Seed 103 · Age guidance, not curriculum certification