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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: 8, 11, ____, 17, 20.
2. Find the missing number in the sequence: 17, 25, ____, 41, 49.
3. Find the missing number in the sequence: 9, 16, ____, 30, 37.
4. Find the missing number in the sequence: 3, 11, ____, 27, 35.
5. Find the missing number in the sequence: 13, 22, ____, 40, 49.
6. Find the missing number in the sequence: 16, 25, ____, 43, 52.
7. Find the missing number in the sequence: 6, 13, ____, 27, 34.
8. Find the missing number in the sequence: 1, 9, ____, 25, 33.
9. Find the missing number in the sequence: 10, 13, ____, 19, 22.
10. Find the missing number in the sequence: 17, 27, ____, 47, 57.
11. Find the missing number in the sequence: 3, 10, ____, 24, 31.
12. Find the missing number in the sequence: 13, 19, ____, 31, 37.
12 questions · Seed 101 · 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: 8, 11, ____, 17, 20.
14The sequence increases by 3 each step: 11 + 3 = 14.
2. Find the missing number in the sequence: 17, 25, ____, 41, 49.
33The sequence increases by 8 each step: 25 + 8 = 33.
3. Find the missing number in the sequence: 9, 16, ____, 30, 37.
23The sequence increases by 7 each step: 16 + 7 = 23.
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: 13, 22, ____, 40, 49.
31The sequence increases by 9 each step: 22 + 9 = 31.
6. Find the missing number in the sequence: 16, 25, ____, 43, 52.
34The sequence increases by 9 each step: 25 + 9 = 34.
7. Find the missing number in the sequence: 6, 13, ____, 27, 34.
20The sequence increases by 7 each step: 13 + 7 = 20.
8. Find the missing number in the sequence: 1, 9, ____, 25, 33.
17The sequence increases by 8 each step: 9 + 8 = 17.
9. Find the missing number in the sequence: 10, 13, ____, 19, 22.
16The sequence increases by 3 each step: 13 + 3 = 16.
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: 3, 10, ____, 24, 31.
17The sequence increases by 7 each step: 10 + 7 = 17.
12. Find the missing number in the sequence: 13, 19, ____, 31, 37.
25The sequence increases by 6 each step: 19 + 6 = 25.
12 questions · Seed 101 · 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: 8, 11, ____, 17, 20.
2. Find the missing number in the sequence: 17, 25, ____, 41, 49.
3. Find the missing number in the sequence: 9, 16, ____, 30, 37.
4. Find the missing number in the sequence: 3, 11, ____, 27, 35.
5. Find the missing number in the sequence: 13, 22, ____, 40, 49.
6. Find the missing number in the sequence: 16, 25, ____, 43, 52.
7. Find the missing number in the sequence: 6, 13, ____, 27, 34.
8. Find the missing number in the sequence: 1, 9, ____, 25, 33.
9. Find the missing number in the sequence: 10, 13, ____, 19, 22.
10. Find the missing number in the sequence: 17, 27, ____, 47, 57.
11. Find the missing number in the sequence: 3, 10, ____, 24, 31.
12. Find the missing number in the sequence: 13, 19, ____, 31, 37.
12 questions · Seed 101 · 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: 8, 11, ____, 17, 20.
14The sequence increases by 3 each step: 11 + 3 = 14.
2. Find the missing number in the sequence: 17, 25, ____, 41, 49.
33The sequence increases by 8 each step: 25 + 8 = 33.
3. Find the missing number in the sequence: 9, 16, ____, 30, 37.
23The sequence increases by 7 each step: 16 + 7 = 23.
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: 13, 22, ____, 40, 49.
31The sequence increases by 9 each step: 22 + 9 = 31.
6. Find the missing number in the sequence: 16, 25, ____, 43, 52.
34The sequence increases by 9 each step: 25 + 9 = 34.
7. Find the missing number in the sequence: 6, 13, ____, 27, 34.
20The sequence increases by 7 each step: 13 + 7 = 20.
8. Find the missing number in the sequence: 1, 9, ____, 25, 33.
17The sequence increases by 8 each step: 9 + 8 = 17.
9. Find the missing number in the sequence: 10, 13, ____, 19, 22.
16The sequence increases by 3 each step: 13 + 3 = 16.
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: 3, 10, ____, 24, 31.
17The sequence increases by 7 each step: 10 + 7 = 17.
12. Find the missing number in the sequence: 13, 19, ____, 31, 37.
25The sequence increases by 6 each step: 19 + 6 = 25.
12 questions · Seed 101 · Age guidance, not curriculum certification