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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: 1, 9, ____, 25, 33.
2. Find the missing number in the sequence: 3, 11, ____, 27, 35.
3. Find the missing number in the sequence: 2, 6, ____, 14, 18.
4. Find the missing number in the sequence: 14, 20, ____, 32, 38.
5. Find the missing number in the sequence: 7, 17, ____, 37, 47.
6. Find the missing number in the sequence: 8, 16, ____, 32, 40.
7. Find the missing number in the sequence: 9, 18, ____, 36, 45.
8. Find the missing number in the sequence: 16, 25, ____, 43, 52.
9. Find the missing number in the sequence: 20, 23, ____, 29, 32.
10. Find the missing number in the sequence: 8, 18, ____, 38, 48.
11. Find the missing number in the sequence: 18, 28, ____, 48, 58.
12. Find the missing number in the sequence: 3, 13, ____, 33, 43.
12 questions · Seed 47 · 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: 1, 9, ____, 25, 33.
17The sequence increases by 8 each step: 9 + 8 = 17.
2. Find the missing number in the sequence: 3, 11, ____, 27, 35.
19The sequence increases by 8 each step: 11 + 8 = 19.
3. Find the missing number in the sequence: 2, 6, ____, 14, 18.
10The sequence increases by 4 each step: 6 + 4 = 10.
4. Find the missing number in the sequence: 14, 20, ____, 32, 38.
26The sequence increases by 6 each step: 20 + 6 = 26.
5. Find the missing number in the sequence: 7, 17, ____, 37, 47.
27The sequence increases by 10 each step: 17 + 10 = 27.
6. Find the missing number in the sequence: 8, 16, ____, 32, 40.
24The sequence increases by 8 each step: 16 + 8 = 24.
7. Find the missing number in the sequence: 9, 18, ____, 36, 45.
27The sequence increases by 9 each step: 18 + 9 = 27.
8. Find the missing number in the sequence: 16, 25, ____, 43, 52.
34The sequence increases by 9 each step: 25 + 9 = 34.
9. Find the missing number in the sequence: 20, 23, ____, 29, 32.
26The sequence increases by 3 each step: 23 + 3 = 26.
10. Find the missing number in the sequence: 8, 18, ____, 38, 48.
28The sequence increases by 10 each step: 18 + 10 = 28.
11. Find the missing number in the sequence: 18, 28, ____, 48, 58.
38The sequence increases by 10 each step: 28 + 10 = 38.
12. Find the missing number in the sequence: 3, 13, ____, 33, 43.
23The sequence increases by 10 each step: 13 + 10 = 23.
12 questions · Seed 47 · 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: 1, 9, ____, 25, 33.
2. Find the missing number in the sequence: 3, 11, ____, 27, 35.
3. Find the missing number in the sequence: 2, 6, ____, 14, 18.
4. Find the missing number in the sequence: 14, 20, ____, 32, 38.
5. Find the missing number in the sequence: 7, 17, ____, 37, 47.
6. Find the missing number in the sequence: 8, 16, ____, 32, 40.
7. Find the missing number in the sequence: 9, 18, ____, 36, 45.
8. Find the missing number in the sequence: 16, 25, ____, 43, 52.
9. Find the missing number in the sequence: 20, 23, ____, 29, 32.
10. Find the missing number in the sequence: 8, 18, ____, 38, 48.
11. Find the missing number in the sequence: 18, 28, ____, 48, 58.
12. Find the missing number in the sequence: 3, 13, ____, 33, 43.
12 questions · Seed 47 · 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: 1, 9, ____, 25, 33.
17The sequence increases by 8 each step: 9 + 8 = 17.
2. Find the missing number in the sequence: 3, 11, ____, 27, 35.
19The sequence increases by 8 each step: 11 + 8 = 19.
3. Find the missing number in the sequence: 2, 6, ____, 14, 18.
10The sequence increases by 4 each step: 6 + 4 = 10.
4. Find the missing number in the sequence: 14, 20, ____, 32, 38.
26The sequence increases by 6 each step: 20 + 6 = 26.
5. Find the missing number in the sequence: 7, 17, ____, 37, 47.
27The sequence increases by 10 each step: 17 + 10 = 27.
6. Find the missing number in the sequence: 8, 16, ____, 32, 40.
24The sequence increases by 8 each step: 16 + 8 = 24.
7. Find the missing number in the sequence: 9, 18, ____, 36, 45.
27The sequence increases by 9 each step: 18 + 9 = 27.
8. Find the missing number in the sequence: 16, 25, ____, 43, 52.
34The sequence increases by 9 each step: 25 + 9 = 34.
9. Find the missing number in the sequence: 20, 23, ____, 29, 32.
26The sequence increases by 3 each step: 23 + 3 = 26.
10. Find the missing number in the sequence: 8, 18, ____, 38, 48.
28The sequence increases by 10 each step: 18 + 10 = 28.
11. Find the missing number in the sequence: 18, 28, ____, 48, 58.
38The sequence increases by 10 each step: 28 + 10 = 38.
12. Find the missing number in the sequence: 3, 13, ____, 33, 43.
23The sequence increases by 10 each step: 13 + 10 = 23.
12 questions · Seed 47 · Age guidance, not curriculum certification