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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: 17, 24, ____, 38, 45.
2. Find the missing number in the sequence: 16, 26, ____, 46, 56.
3. Find the missing number in the sequence: 1, 5, ____, 13, 17.
4. Find the missing number in the sequence: 14, 18, ____, 26, 30.
5. Find the missing number in the sequence: 13, 23, ____, 43, 53.
6. Find the missing number in the sequence: 15, 24, ____, 42, 51.
7. Find the missing number in the sequence: 8, 17, ____, 35, 44.
8. Find the missing number in the sequence: 19, 22, ____, 28, 31.
9. Find the missing number in the sequence: 12, 19, ____, 33, 40.
10. Find the missing number in the sequence: 16, 25, ____, 43, 52.
11. Find the missing number in the sequence: 11, 20, ____, 38, 47.
12. Find the missing number in the sequence: 11, 19, ____, 35, 43.
12 questions · Seed 80 · 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: 17, 24, ____, 38, 45.
31The sequence increases by 7 each step: 24 + 7 = 31.
2. Find the missing number in the sequence: 16, 26, ____, 46, 56.
36The sequence increases by 10 each step: 26 + 10 = 36.
3. Find the missing number in the sequence: 1, 5, ____, 13, 17.
9The sequence increases by 4 each step: 5 + 4 = 9.
4. Find the missing number in the sequence: 14, 18, ____, 26, 30.
22The sequence increases by 4 each step: 18 + 4 = 22.
5. Find the missing number in the sequence: 13, 23, ____, 43, 53.
33The sequence increases by 10 each step: 23 + 10 = 33.
6. Find the missing number in the sequence: 15, 24, ____, 42, 51.
33The sequence increases by 9 each step: 24 + 9 = 33.
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: 19, 22, ____, 28, 31.
25The sequence increases by 3 each step: 22 + 3 = 25.
9. Find the missing number in the sequence: 12, 19, ____, 33, 40.
26The sequence increases by 7 each step: 19 + 7 = 26.
10. Find the missing number in the sequence: 16, 25, ____, 43, 52.
34The sequence increases by 9 each step: 25 + 9 = 34.
11. Find the missing number in the sequence: 11, 20, ____, 38, 47.
29The sequence increases by 9 each step: 20 + 9 = 29.
12. Find the missing number in the sequence: 11, 19, ____, 35, 43.
27The sequence increases by 8 each step: 19 + 8 = 27.
12 questions · Seed 80 · 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: 17, 24, ____, 38, 45.
2. Find the missing number in the sequence: 16, 26, ____, 46, 56.
3. Find the missing number in the sequence: 1, 5, ____, 13, 17.
4. Find the missing number in the sequence: 14, 18, ____, 26, 30.
5. Find the missing number in the sequence: 13, 23, ____, 43, 53.
6. Find the missing number in the sequence: 15, 24, ____, 42, 51.
7. Find the missing number in the sequence: 8, 17, ____, 35, 44.
8. Find the missing number in the sequence: 19, 22, ____, 28, 31.
9. Find the missing number in the sequence: 12, 19, ____, 33, 40.
10. Find the missing number in the sequence: 16, 25, ____, 43, 52.
11. Find the missing number in the sequence: 11, 20, ____, 38, 47.
12. Find the missing number in the sequence: 11, 19, ____, 35, 43.
12 questions · Seed 80 · 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: 17, 24, ____, 38, 45.
31The sequence increases by 7 each step: 24 + 7 = 31.
2. Find the missing number in the sequence: 16, 26, ____, 46, 56.
36The sequence increases by 10 each step: 26 + 10 = 36.
3. Find the missing number in the sequence: 1, 5, ____, 13, 17.
9The sequence increases by 4 each step: 5 + 4 = 9.
4. Find the missing number in the sequence: 14, 18, ____, 26, 30.
22The sequence increases by 4 each step: 18 + 4 = 22.
5. Find the missing number in the sequence: 13, 23, ____, 43, 53.
33The sequence increases by 10 each step: 23 + 10 = 33.
6. Find the missing number in the sequence: 15, 24, ____, 42, 51.
33The sequence increases by 9 each step: 24 + 9 = 33.
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: 19, 22, ____, 28, 31.
25The sequence increases by 3 each step: 22 + 3 = 25.
9. Find the missing number in the sequence: 12, 19, ____, 33, 40.
26The sequence increases by 7 each step: 19 + 7 = 26.
10. Find the missing number in the sequence: 16, 25, ____, 43, 52.
34The sequence increases by 9 each step: 25 + 9 = 34.
11. Find the missing number in the sequence: 11, 20, ____, 38, 47.
29The sequence increases by 9 each step: 20 + 9 = 29.
12. Find the missing number in the sequence: 11, 19, ____, 35, 43.
27The sequence increases by 8 each step: 19 + 8 = 27.
12 questions · Seed 80 · Age guidance, not curriculum certification