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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: 5, 12, ____, 26, 33.
2. Find the missing number in the sequence: 19, 23, ____, 31, 35.
3. Find the missing number in the sequence: 17, 27, ____, 47, 57.
4. Find the missing number in the sequence: 20, 23, ____, 29, 32.
5. Find the missing number in the sequence: 16, 26, ____, 46, 56.
6. Find the missing number in the sequence: 15, 18, ____, 24, 27.
7. Find the missing number in the sequence: 4, 14, ____, 34, 44.
8. Find the missing number in the sequence: 19, 29, ____, 49, 59.
9. Find the missing number in the sequence: 1, 8, ____, 22, 29.
10. Find the missing number in the sequence: 7, 11, ____, 19, 23.
11. Find the missing number in the sequence: 9, 18, ____, 36, 45.
12. Find the missing number in the sequence: 8, 16, ____, 32, 40.
12 questions · Seed 102 · 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: 5, 12, ____, 26, 33.
19The sequence increases by 7 each step: 12 + 7 = 19.
2. Find the missing number in the sequence: 19, 23, ____, 31, 35.
27The sequence increases by 4 each step: 23 + 4 = 27.
3. Find the missing number in the sequence: 17, 27, ____, 47, 57.
37The sequence increases by 10 each step: 27 + 10 = 37.
4. Find the missing number in the sequence: 20, 23, ____, 29, 32.
26The sequence increases by 3 each step: 23 + 3 = 26.
5. Find the missing number in the sequence: 16, 26, ____, 46, 56.
36The sequence increases by 10 each step: 26 + 10 = 36.
6. Find the missing number in the sequence: 15, 18, ____, 24, 27.
21The sequence increases by 3 each step: 18 + 3 = 21.
7. Find the missing number in the sequence: 4, 14, ____, 34, 44.
24The sequence increases by 10 each step: 14 + 10 = 24.
8. Find the missing number in the sequence: 19, 29, ____, 49, 59.
39The sequence increases by 10 each step: 29 + 10 = 39.
9. Find the missing number in the sequence: 1, 8, ____, 22, 29.
15The sequence increases by 7 each step: 8 + 7 = 15.
10. Find the missing number in the sequence: 7, 11, ____, 19, 23.
15The sequence increases by 4 each step: 11 + 4 = 15.
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: 8, 16, ____, 32, 40.
24The sequence increases by 8 each step: 16 + 8 = 24.
12 questions · Seed 102 · 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: 5, 12, ____, 26, 33.
2. Find the missing number in the sequence: 19, 23, ____, 31, 35.
3. Find the missing number in the sequence: 17, 27, ____, 47, 57.
4. Find the missing number in the sequence: 20, 23, ____, 29, 32.
5. Find the missing number in the sequence: 16, 26, ____, 46, 56.
6. Find the missing number in the sequence: 15, 18, ____, 24, 27.
7. Find the missing number in the sequence: 4, 14, ____, 34, 44.
8. Find the missing number in the sequence: 19, 29, ____, 49, 59.
9. Find the missing number in the sequence: 1, 8, ____, 22, 29.
10. Find the missing number in the sequence: 7, 11, ____, 19, 23.
11. Find the missing number in the sequence: 9, 18, ____, 36, 45.
12. Find the missing number in the sequence: 8, 16, ____, 32, 40.
12 questions · Seed 102 · 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: 5, 12, ____, 26, 33.
19The sequence increases by 7 each step: 12 + 7 = 19.
2. Find the missing number in the sequence: 19, 23, ____, 31, 35.
27The sequence increases by 4 each step: 23 + 4 = 27.
3. Find the missing number in the sequence: 17, 27, ____, 47, 57.
37The sequence increases by 10 each step: 27 + 10 = 37.
4. Find the missing number in the sequence: 20, 23, ____, 29, 32.
26The sequence increases by 3 each step: 23 + 3 = 26.
5. Find the missing number in the sequence: 16, 26, ____, 46, 56.
36The sequence increases by 10 each step: 26 + 10 = 36.
6. Find the missing number in the sequence: 15, 18, ____, 24, 27.
21The sequence increases by 3 each step: 18 + 3 = 21.
7. Find the missing number in the sequence: 4, 14, ____, 34, 44.
24The sequence increases by 10 each step: 14 + 10 = 24.
8. Find the missing number in the sequence: 19, 29, ____, 49, 59.
39The sequence increases by 10 each step: 29 + 10 = 39.
9. Find the missing number in the sequence: 1, 8, ____, 22, 29.
15The sequence increases by 7 each step: 8 + 7 = 15.
10. Find the missing number in the sequence: 7, 11, ____, 19, 23.
15The sequence increases by 4 each step: 11 + 4 = 15.
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: 8, 16, ____, 32, 40.
24The sequence increases by 8 each step: 16 + 8 = 24.
12 questions · Seed 102 · Age guidance, not curriculum certification