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 104 · 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: 20, 25, ____, 35, 40.
30
The sequence increases by 5 each step: 25 + 5 = 30.
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: 15, 17, ____, 21, 23.
19
The sequence increases by 2 each step: 17 + 2 = 19.
4. Find the missing number in the sequence: 9, 11, ____, 15, 17.
13
The sequence increases by 2 each step: 11 + 2 = 13.
5. Find the missing number in the sequence: 5, 10, ____, 20, 25.
15
The sequence increases by 5 each step: 10 + 5 = 15.
6. Find the missing number in the sequence: 9, 10, ____, 12, 13.
11
The sequence increases by 1 each step: 10 + 1 = 11.
7. Find the missing number in the sequence: 2, 7, ____, 17, 22.
12
The sequence increases by 5 each step: 7 + 5 = 12.
8. Find the missing number in the sequence: 8, 13, ____, 23, 28.
18
The sequence increases by 5 each step: 13 + 5 = 18.
9. Find the missing number in the sequence: 11, 16, ____, 26, 31.
21
The sequence increases by 5 each step: 16 + 5 = 21.
10. Find the missing number in the sequence: 1, 2, ____, 4, 5.
3
The sequence increases by 1 each step: 2 + 1 = 3.
11. Find the missing number in the sequence: 6, 7, ____, 9, 10.
8
The sequence increases by 1 each step: 7 + 1 = 8.
12. Find the missing number in the sequence: 10, 11, ____, 13, 14.
12
The sequence increases by 1 each step: 11 + 1 = 12.

12 questions · Seed 104 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 4-6

Take your time. Show your thinking.

12 questions · Seed 104 · 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: 20, 25, ____, 35, 40.
30
The sequence increases by 5 each step: 25 + 5 = 30.
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: 15, 17, ____, 21, 23.
19
The sequence increases by 2 each step: 17 + 2 = 19.
4. Find the missing number in the sequence: 9, 11, ____, 15, 17.
13
The sequence increases by 2 each step: 11 + 2 = 13.
5. Find the missing number in the sequence: 5, 10, ____, 20, 25.
15
The sequence increases by 5 each step: 10 + 5 = 15.
6. Find the missing number in the sequence: 9, 10, ____, 12, 13.
11
The sequence increases by 1 each step: 10 + 1 = 11.
7. Find the missing number in the sequence: 2, 7, ____, 17, 22.
12
The sequence increases by 5 each step: 7 + 5 = 12.
8. Find the missing number in the sequence: 8, 13, ____, 23, 28.
18
The sequence increases by 5 each step: 13 + 5 = 18.
9. Find the missing number in the sequence: 11, 16, ____, 26, 31.
21
The sequence increases by 5 each step: 16 + 5 = 21.
10. Find the missing number in the sequence: 1, 2, ____, 4, 5.
3
The sequence increases by 1 each step: 2 + 1 = 3.
11. Find the missing number in the sequence: 6, 7, ____, 9, 10.
8
The sequence increases by 1 each step: 7 + 1 = 8.
12. Find the missing number in the sequence: 10, 11, ____, 13, 14.
12
The sequence increases by 1 each step: 11 + 1 = 12.

12 questions · Seed 104 · Age guidance, not curriculum certification