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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, 17, ____, 25, 29.
2. Find the missing number in the sequence: 12, 19, ____, 33, 40.
3. Find the missing number in the sequence: 14, 18, ____, 26, 30.
4. Find the missing number in the sequence: 7, 10, ____, 16, 19.
5. Find the missing number in the sequence: 4, 7, ____, 13, 16.
6. Find the missing number in the sequence: 4, 13, ____, 31, 40.
7. Find the missing number in the sequence: 8, 17, ____, 35, 44.
8. Find the missing number in the sequence: 10, 18, ____, 34, 42.
9. Find the missing number in the sequence: 6, 10, ____, 18, 22.
10. Find the missing number in the sequence: 11, 18, ____, 32, 39.
11. Find the missing number in the sequence: 3, 12, ____, 30, 39.
12. Find the missing number in the sequence: 9, 15, ____, 27, 33.
12 questions · Seed 55 · 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, 17, ____, 25, 29.
21The sequence increases by 4 each step: 17 + 4 = 21.
2. Find the missing number in the sequence: 12, 19, ____, 33, 40.
26The sequence increases by 7 each step: 19 + 7 = 26.
3. Find the missing number in the sequence: 14, 18, ____, 26, 30.
22The sequence increases by 4 each step: 18 + 4 = 22.
4. Find the missing number in the sequence: 7, 10, ____, 16, 19.
13The sequence increases by 3 each step: 10 + 3 = 13.
5. Find the missing number in the sequence: 4, 7, ____, 13, 16.
10The sequence increases by 3 each step: 7 + 3 = 10.
6. Find the missing number in the sequence: 4, 13, ____, 31, 40.
22The sequence increases by 9 each step: 13 + 9 = 22.
7. Find the missing number in the sequence: 8, 17, ____, 35, 44.
26The sequence increases by 9 each step: 17 + 9 = 26.
8. Find the missing number in the sequence: 10, 18, ____, 34, 42.
26The sequence increases by 8 each step: 18 + 8 = 26.
9. Find the missing number in the sequence: 6, 10, ____, 18, 22.
14The sequence increases by 4 each step: 10 + 4 = 14.
10. Find the missing number in the sequence: 11, 18, ____, 32, 39.
25The sequence increases by 7 each step: 18 + 7 = 25.
11. Find the missing number in the sequence: 3, 12, ____, 30, 39.
21The sequence increases by 9 each step: 12 + 9 = 21.
12. Find the missing number in the sequence: 9, 15, ____, 27, 33.
21The sequence increases by 6 each step: 15 + 6 = 21.
12 questions · Seed 55 · 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, 17, ____, 25, 29.
2. Find the missing number in the sequence: 12, 19, ____, 33, 40.
3. Find the missing number in the sequence: 14, 18, ____, 26, 30.
4. Find the missing number in the sequence: 7, 10, ____, 16, 19.
5. Find the missing number in the sequence: 4, 7, ____, 13, 16.
6. Find the missing number in the sequence: 4, 13, ____, 31, 40.
7. Find the missing number in the sequence: 8, 17, ____, 35, 44.
8. Find the missing number in the sequence: 10, 18, ____, 34, 42.
9. Find the missing number in the sequence: 6, 10, ____, 18, 22.
10. Find the missing number in the sequence: 11, 18, ____, 32, 39.
11. Find the missing number in the sequence: 3, 12, ____, 30, 39.
12. Find the missing number in the sequence: 9, 15, ____, 27, 33.
12 questions · Seed 55 · 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, 17, ____, 25, 29.
21The sequence increases by 4 each step: 17 + 4 = 21.
2. Find the missing number in the sequence: 12, 19, ____, 33, 40.
26The sequence increases by 7 each step: 19 + 7 = 26.
3. Find the missing number in the sequence: 14, 18, ____, 26, 30.
22The sequence increases by 4 each step: 18 + 4 = 22.
4. Find the missing number in the sequence: 7, 10, ____, 16, 19.
13The sequence increases by 3 each step: 10 + 3 = 13.
5. Find the missing number in the sequence: 4, 7, ____, 13, 16.
10The sequence increases by 3 each step: 7 + 3 = 10.
6. Find the missing number in the sequence: 4, 13, ____, 31, 40.
22The sequence increases by 9 each step: 13 + 9 = 22.
7. Find the missing number in the sequence: 8, 17, ____, 35, 44.
26The sequence increases by 9 each step: 17 + 9 = 26.
8. Find the missing number in the sequence: 10, 18, ____, 34, 42.
26The sequence increases by 8 each step: 18 + 8 = 26.
9. Find the missing number in the sequence: 6, 10, ____, 18, 22.
14The sequence increases by 4 each step: 10 + 4 = 14.
10. Find the missing number in the sequence: 11, 18, ____, 32, 39.
25The sequence increases by 7 each step: 18 + 7 = 25.
11. Find the missing number in the sequence: 3, 12, ____, 30, 39.
21The sequence increases by 9 each step: 12 + 9 = 21.
12. Find the missing number in the sequence: 9, 15, ____, 27, 33.
21The sequence increases by 6 each step: 15 + 6 = 21.
12 questions · Seed 55 · Age guidance, not curriculum certification