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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: 9, 18, ____, 36, 45.
2. Find the missing number in the sequence: 5, 12, ____, 26, 33.
3. Find the missing number in the sequence: 8, 12, ____, 20, 24.
4. Find the missing number in the sequence: 13, 22, ____, 40, 49.
5. Find the missing number in the sequence: 11, 19, ____, 35, 43.
6. Find the missing number in the sequence: 3, 7, ____, 15, 19.
7. Find the missing number in the sequence: 2, 11, ____, 29, 38.
8. Find the missing number in the sequence: 2, 6, ____, 14, 18.
9. Find the missing number in the sequence: 5, 9, ____, 17, 21.
10. Find the missing number in the sequence: 1, 9, ____, 25, 33.
11. Find the missing number in the sequence: 17, 27, ____, 47, 57.
12. Find the missing number in the sequence: 9, 15, ____, 27, 33.
12 questions · Seed 104744 · 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: 9, 18, ____, 36, 45.
27The sequence increases by 9 each step: 18 + 9 = 27.
2. Find the missing number in the sequence: 5, 12, ____, 26, 33.
19The sequence increases by 7 each step: 12 + 7 = 19.
3. Find the missing number in the sequence: 8, 12, ____, 20, 24.
16The sequence increases by 4 each step: 12 + 4 = 16.
4. Find the missing number in the sequence: 13, 22, ____, 40, 49.
31The sequence increases by 9 each step: 22 + 9 = 31.
5. Find the missing number in the sequence: 11, 19, ____, 35, 43.
27The sequence increases by 8 each step: 19 + 8 = 27.
6. Find the missing number in the sequence: 3, 7, ____, 15, 19.
11The sequence increases by 4 each step: 7 + 4 = 11.
7. Find the missing number in the sequence: 2, 11, ____, 29, 38.
20The sequence increases by 9 each step: 11 + 9 = 20.
8. Find the missing number in the sequence: 2, 6, ____, 14, 18.
10The sequence increases by 4 each step: 6 + 4 = 10.
9. Find the missing number in the sequence: 5, 9, ____, 17, 21.
13The sequence increases by 4 each step: 9 + 4 = 13.
10. Find the missing number in the sequence: 1, 9, ____, 25, 33.
17The sequence increases by 8 each step: 9 + 8 = 17.
11. Find the missing number in the sequence: 17, 27, ____, 47, 57.
37The sequence increases by 10 each step: 27 + 10 = 37.
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 104744 · 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: 9, 18, ____, 36, 45.
2. Find the missing number in the sequence: 5, 12, ____, 26, 33.
3. Find the missing number in the sequence: 8, 12, ____, 20, 24.
4. Find the missing number in the sequence: 13, 22, ____, 40, 49.
5. Find the missing number in the sequence: 11, 19, ____, 35, 43.
6. Find the missing number in the sequence: 3, 7, ____, 15, 19.
7. Find the missing number in the sequence: 2, 11, ____, 29, 38.
8. Find the missing number in the sequence: 2, 6, ____, 14, 18.
9. Find the missing number in the sequence: 5, 9, ____, 17, 21.
10. Find the missing number in the sequence: 1, 9, ____, 25, 33.
11. Find the missing number in the sequence: 17, 27, ____, 47, 57.
12. Find the missing number in the sequence: 9, 15, ____, 27, 33.
12 questions · Seed 104744 · 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: 9, 18, ____, 36, 45.
27The sequence increases by 9 each step: 18 + 9 = 27.
2. Find the missing number in the sequence: 5, 12, ____, 26, 33.
19The sequence increases by 7 each step: 12 + 7 = 19.
3. Find the missing number in the sequence: 8, 12, ____, 20, 24.
16The sequence increases by 4 each step: 12 + 4 = 16.
4. Find the missing number in the sequence: 13, 22, ____, 40, 49.
31The sequence increases by 9 each step: 22 + 9 = 31.
5. Find the missing number in the sequence: 11, 19, ____, 35, 43.
27The sequence increases by 8 each step: 19 + 8 = 27.
6. Find the missing number in the sequence: 3, 7, ____, 15, 19.
11The sequence increases by 4 each step: 7 + 4 = 11.
7. Find the missing number in the sequence: 2, 11, ____, 29, 38.
20The sequence increases by 9 each step: 11 + 9 = 20.
8. Find the missing number in the sequence: 2, 6, ____, 14, 18.
10The sequence increases by 4 each step: 6 + 4 = 10.
9. Find the missing number in the sequence: 5, 9, ____, 17, 21.
13The sequence increases by 4 each step: 9 + 4 = 13.
10. Find the missing number in the sequence: 1, 9, ____, 25, 33.
17The sequence increases by 8 each step: 9 + 8 = 17.
11. Find the missing number in the sequence: 17, 27, ____, 47, 57.
37The sequence increases by 10 each step: 27 + 10 = 37.
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 104744 · Age guidance, not curriculum certification