Back to worksheetsReasoningAges 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.
Worksheet StudioPractice pack · Ages 7-9
Missing sequence terms
Take your time. Show your thinking.
1. Find the missing number in the sequence: 19, 28, ____, 46, 55.
2. Find the missing number in the sequence: 13, 17, ____, 25, 29.
3. Find the missing number in the sequence: 1, 11, ____, 31, 41.
4. Find the missing number in the sequence: 3, 11, ____, 27, 35.
5. Find the missing number in the sequence: 9, 13, ____, 21, 25.
6. Find the missing number in the sequence: 12, 20, ____, 36, 44.
7. Find the missing number in the sequence: 15, 21, ____, 33, 39.
8. Find the missing number in the sequence: 8, 18, ____, 38, 48.
9. Find the missing number in the sequence: 5, 14, ____, 32, 41.
10. Find the missing number in the sequence: 17, 27, ____, 47, 57.
11. Find the missing number in the sequence: 2, 11, ____, 29, 38.
12. Find the missing number in the sequence: 19, 25, ____, 37, 43.
12 questions · Seed 90 · Age guidance, not curriculum certification
View the answer key
Worksheet StudioAnswer key · Ages 7-9
Missing sequence terms
Answers and reasoning. Review before teaching.
1. Find the missing number in the sequence: 19, 28, ____, 46, 55.
37The sequence increases by 9 each step: 28 + 9 = 37.
2. Find the missing number in the sequence: 13, 17, ____, 25, 29.
21The sequence increases by 4 each step: 17 + 4 = 21.
3. Find the missing number in the sequence: 1, 11, ____, 31, 41.
21The sequence increases by 10 each step: 11 + 10 = 21.
4. Find the missing number in the sequence: 3, 11, ____, 27, 35.
19The sequence increases by 8 each step: 11 + 8 = 19.
5. Find the missing number in the sequence: 9, 13, ____, 21, 25.
17The sequence increases by 4 each step: 13 + 4 = 17.
6. Find the missing number in the sequence: 12, 20, ____, 36, 44.
28The sequence increases by 8 each step: 20 + 8 = 28.
7. Find the missing number in the sequence: 15, 21, ____, 33, 39.
27The sequence increases by 6 each step: 21 + 6 = 27.
8. Find the missing number in the sequence: 8, 18, ____, 38, 48.
28The sequence increases by 10 each step: 18 + 10 = 28.
9. Find the missing number in the sequence: 5, 14, ____, 32, 41.
23The sequence increases by 9 each step: 14 + 9 = 23.
10. Find the missing number in the sequence: 17, 27, ____, 47, 57.
37The sequence increases by 10 each step: 27 + 10 = 37.
11. Find the missing number in the sequence: 2, 11, ____, 29, 38.
20The sequence increases by 9 each step: 11 + 9 = 20.
12. Find the missing number in the sequence: 19, 25, ____, 37, 43.
31The sequence increases by 6 each step: 25 + 6 = 31.
12 questions · Seed 90 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 7-9
Missing sequence terms
Take your time. Show your thinking.
1. Find the missing number in the sequence: 19, 28, ____, 46, 55.
2. Find the missing number in the sequence: 13, 17, ____, 25, 29.
3. Find the missing number in the sequence: 1, 11, ____, 31, 41.
4. Find the missing number in the sequence: 3, 11, ____, 27, 35.
5. Find the missing number in the sequence: 9, 13, ____, 21, 25.
6. Find the missing number in the sequence: 12, 20, ____, 36, 44.
7. Find the missing number in the sequence: 15, 21, ____, 33, 39.
8. Find the missing number in the sequence: 8, 18, ____, 38, 48.
9. Find the missing number in the sequence: 5, 14, ____, 32, 41.
10. Find the missing number in the sequence: 17, 27, ____, 47, 57.
11. Find the missing number in the sequence: 2, 11, ____, 29, 38.
12. Find the missing number in the sequence: 19, 25, ____, 37, 43.
12 questions · Seed 90 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 7-9
Missing sequence terms
Answers and reasoning. Review before teaching.
1. Find the missing number in the sequence: 19, 28, ____, 46, 55.
37The sequence increases by 9 each step: 28 + 9 = 37.
2. Find the missing number in the sequence: 13, 17, ____, 25, 29.
21The sequence increases by 4 each step: 17 + 4 = 21.
3. Find the missing number in the sequence: 1, 11, ____, 31, 41.
21The sequence increases by 10 each step: 11 + 10 = 21.
4. Find the missing number in the sequence: 3, 11, ____, 27, 35.
19The sequence increases by 8 each step: 11 + 8 = 19.
5. Find the missing number in the sequence: 9, 13, ____, 21, 25.
17The sequence increases by 4 each step: 13 + 4 = 17.
6. Find the missing number in the sequence: 12, 20, ____, 36, 44.
28The sequence increases by 8 each step: 20 + 8 = 28.
7. Find the missing number in the sequence: 15, 21, ____, 33, 39.
27The sequence increases by 6 each step: 21 + 6 = 27.
8. Find the missing number in the sequence: 8, 18, ____, 38, 48.
28The sequence increases by 10 each step: 18 + 10 = 28.
9. Find the missing number in the sequence: 5, 14, ____, 32, 41.
23The sequence increases by 9 each step: 14 + 9 = 23.
10. Find the missing number in the sequence: 17, 27, ____, 47, 57.
37The sequence increases by 10 each step: 27 + 10 = 37.
11. Find the missing number in the sequence: 2, 11, ____, 29, 38.
20The sequence increases by 9 each step: 11 + 9 = 20.
12. Find the missing number in the sequence: 19, 25, ____, 37, 43.
31The sequence increases by 6 each step: 25 + 6 = 31.
12 questions · Seed 90 · Age guidance, not curriculum certification