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.

Choose “Save as PDF” to keep a copy. Use your browser’s paper setting for A4 or Letter.

Worksheet StudioPractice pack · Ages 4-6

Take your time. Show your thinking.

12 questions · Seed 105 · 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, 22, ____, 26, 28.
24
The sequence increases by 2 each step: 22 + 2 = 24.
2. Find the missing number in the sequence: 20, 21, ____, 23, 24.
22
The sequence increases by 1 each step: 21 + 1 = 22.
3. Find the missing number in the sequence: 13, 18, ____, 28, 33.
23
The sequence increases by 5 each step: 18 + 5 = 23.
4. Find the missing number in the sequence: 11, 16, ____, 26, 31.
21
The sequence increases by 5 each step: 16 + 5 = 21.
5. Find the missing number in the sequence: 6, 8, ____, 12, 14.
10
The sequence increases by 2 each step: 8 + 2 = 10.
6. Find the missing number in the sequence: 2, 4, ____, 8, 10.
6
The sequence increases by 2 each step: 4 + 2 = 6.
7. Find the missing number in the sequence: 17, 18, ____, 20, 21.
19
The sequence increases by 1 each step: 18 + 1 = 19.
8. Find the missing number in the sequence: 18, 20, ____, 24, 26.
22
The sequence increases by 2 each step: 20 + 2 = 22.
9. Find the missing number in the sequence: 3, 4, ____, 6, 7.
5
The sequence increases by 1 each step: 4 + 1 = 5.
10. Find the missing number in the sequence: 19, 24, ____, 34, 39.
29
The sequence increases by 5 each step: 24 + 5 = 29.
11. Find the missing number in the sequence: 19, 20, ____, 22, 23.
21
The sequence increases by 1 each step: 20 + 1 = 21.
12. Find the missing number in the sequence: 5, 10, ____, 20, 25.
15
The sequence increases by 5 each step: 10 + 5 = 15.

12 questions · Seed 105 · Age guidance, not curriculum certification

Worksheet StudioPractice pack · Ages 4-6

Take your time. Show your thinking.

12 questions · Seed 105 · 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, 22, ____, 26, 28.
24
The sequence increases by 2 each step: 22 + 2 = 24.
2. Find the missing number in the sequence: 20, 21, ____, 23, 24.
22
The sequence increases by 1 each step: 21 + 1 = 22.
3. Find the missing number in the sequence: 13, 18, ____, 28, 33.
23
The sequence increases by 5 each step: 18 + 5 = 23.
4. Find the missing number in the sequence: 11, 16, ____, 26, 31.
21
The sequence increases by 5 each step: 16 + 5 = 21.
5. Find the missing number in the sequence: 6, 8, ____, 12, 14.
10
The sequence increases by 2 each step: 8 + 2 = 10.
6. Find the missing number in the sequence: 2, 4, ____, 8, 10.
6
The sequence increases by 2 each step: 4 + 2 = 6.
7. Find the missing number in the sequence: 17, 18, ____, 20, 21.
19
The sequence increases by 1 each step: 18 + 1 = 19.
8. Find the missing number in the sequence: 18, 20, ____, 24, 26.
22
The sequence increases by 2 each step: 20 + 2 = 22.
9. Find the missing number in the sequence: 3, 4, ____, 6, 7.
5
The sequence increases by 1 each step: 4 + 1 = 5.
10. Find the missing number in the sequence: 19, 24, ____, 34, 39.
29
The sequence increases by 5 each step: 24 + 5 = 29.
11. Find the missing number in the sequence: 19, 20, ____, 22, 23.
21
The sequence increases by 1 each step: 20 + 1 = 21.
12. Find the missing number in the sequence: 5, 10, ____, 20, 25.
15
The sequence increases by 5 each step: 10 + 5 = 15.

12 questions · Seed 105 · Age guidance, not curriculum certification