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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: 13, 20, ____, 34, 41.
2. Find the missing number in the sequence: 6, 12, ____, 24, 30.
3. Find the missing number in the sequence: 1, 4, ____, 10, 13.
4. Find the missing number in the sequence: 10, 17, ____, 31, 38.
5. Find the missing number in the sequence: 8, 17, ____, 35, 44.
6. Find the missing number in the sequence: 12, 22, ____, 42, 52.
7. Find the missing number in the sequence: 7, 16, ____, 34, 43.
8. Find the missing number in the sequence: 5, 11, ____, 23, 29.
9. Find the missing number in the sequence: 3, 10, ____, 24, 31.
10. Find the missing number in the sequence: 6, 13, ____, 27, 34.
11. Find the missing number in the sequence: 9, 18, ____, 36, 45.
12. Find the missing number in the sequence: 20, 26, ____, 38, 44.
12 questions · Seed 67 · 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: 13, 20, ____, 34, 41.
27The sequence increases by 7 each step: 20 + 7 = 27.
2. Find the missing number in the sequence: 6, 12, ____, 24, 30.
18The sequence increases by 6 each step: 12 + 6 = 18.
3. Find the missing number in the sequence: 1, 4, ____, 10, 13.
7The sequence increases by 3 each step: 4 + 3 = 7.
4. Find the missing number in the sequence: 10, 17, ____, 31, 38.
24The sequence increases by 7 each step: 17 + 7 = 24.
5. Find the missing number in the sequence: 8, 17, ____, 35, 44.
26The sequence increases by 9 each step: 17 + 9 = 26.
6. Find the missing number in the sequence: 12, 22, ____, 42, 52.
32The sequence increases by 10 each step: 22 + 10 = 32.
7. Find the missing number in the sequence: 7, 16, ____, 34, 43.
25The sequence increases by 9 each step: 16 + 9 = 25.
8. Find the missing number in the sequence: 5, 11, ____, 23, 29.
17The sequence increases by 6 each step: 11 + 6 = 17.
9. Find the missing number in the sequence: 3, 10, ____, 24, 31.
17The sequence increases by 7 each step: 10 + 7 = 17.
10. Find the missing number in the sequence: 6, 13, ____, 27, 34.
20The sequence increases by 7 each step: 13 + 7 = 20.
11. Find the missing number in the sequence: 9, 18, ____, 36, 45.
27The sequence increases by 9 each step: 18 + 9 = 27.
12. Find the missing number in the sequence: 20, 26, ____, 38, 44.
32The sequence increases by 6 each step: 26 + 6 = 32.
12 questions · Seed 67 · 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: 13, 20, ____, 34, 41.
2. Find the missing number in the sequence: 6, 12, ____, 24, 30.
3. Find the missing number in the sequence: 1, 4, ____, 10, 13.
4. Find the missing number in the sequence: 10, 17, ____, 31, 38.
5. Find the missing number in the sequence: 8, 17, ____, 35, 44.
6. Find the missing number in the sequence: 12, 22, ____, 42, 52.
7. Find the missing number in the sequence: 7, 16, ____, 34, 43.
8. Find the missing number in the sequence: 5, 11, ____, 23, 29.
9. Find the missing number in the sequence: 3, 10, ____, 24, 31.
10. Find the missing number in the sequence: 6, 13, ____, 27, 34.
11. Find the missing number in the sequence: 9, 18, ____, 36, 45.
12. Find the missing number in the sequence: 20, 26, ____, 38, 44.
12 questions · Seed 67 · 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: 13, 20, ____, 34, 41.
27The sequence increases by 7 each step: 20 + 7 = 27.
2. Find the missing number in the sequence: 6, 12, ____, 24, 30.
18The sequence increases by 6 each step: 12 + 6 = 18.
3. Find the missing number in the sequence: 1, 4, ____, 10, 13.
7The sequence increases by 3 each step: 4 + 3 = 7.
4. Find the missing number in the sequence: 10, 17, ____, 31, 38.
24The sequence increases by 7 each step: 17 + 7 = 24.
5. Find the missing number in the sequence: 8, 17, ____, 35, 44.
26The sequence increases by 9 each step: 17 + 9 = 26.
6. Find the missing number in the sequence: 12, 22, ____, 42, 52.
32The sequence increases by 10 each step: 22 + 10 = 32.
7. Find the missing number in the sequence: 7, 16, ____, 34, 43.
25The sequence increases by 9 each step: 16 + 9 = 25.
8. Find the missing number in the sequence: 5, 11, ____, 23, 29.
17The sequence increases by 6 each step: 11 + 6 = 17.
9. Find the missing number in the sequence: 3, 10, ____, 24, 31.
17The sequence increases by 7 each step: 10 + 7 = 17.
10. Find the missing number in the sequence: 6, 13, ____, 27, 34.
20The sequence increases by 7 each step: 13 + 7 = 20.
11. Find the missing number in the sequence: 9, 18, ____, 36, 45.
27The sequence increases by 9 each step: 18 + 9 = 27.
12. Find the missing number in the sequence: 20, 26, ____, 38, 44.
32The sequence increases by 6 each step: 26 + 6 = 32.
12 questions · Seed 67 · Age guidance, not curriculum certification