Back to worksheetsReasoningAges 7-9
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: 12, 18, ____, 30, 36.
2. Find the missing number in the sequence: 15, 19, ____, 27, 31.
3. Find the missing number in the sequence: 1, 4, ____, 10, 13.
4. Find the missing number in the sequence: 12, 15, ____, 21, 24.
5. Find the missing number in the sequence: 1, 7, ____, 19, 25.
6. Find the missing number in the sequence: 8, 14, ____, 26, 32.
7. Find the missing number in the sequence: 2, 11, ____, 29, 38.
8. Find the missing number in the sequence: 10, 14, ____, 22, 26.
9. Find the missing number in the sequence: 13, 22, ____, 40, 49.
10. Find the missing number in the sequence: 10, 13, ____, 19, 22.
11. Find the missing number in the sequence: 16, 25, ____, 43, 52.
12. Find the missing number in the sequence: 11, 15, ____, 23, 27.
12 questions · Seed 70 · 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: 12, 18, ____, 30, 36.
24The sequence increases by 6 each step: 18 + 6 = 24.
2. Find the missing number in the sequence: 15, 19, ____, 27, 31.
23The sequence increases by 4 each step: 19 + 4 = 23.
3. Find the missing number in the sequence: 1, 4, ____, 10, 13.
7The sequence increases by 3 each step: 4 + 3 = 7.
4. Find the missing number in the sequence: 12, 15, ____, 21, 24.
18The sequence increases by 3 each step: 15 + 3 = 18.
5. Find the missing number in the sequence: 1, 7, ____, 19, 25.
13The sequence increases by 6 each step: 7 + 6 = 13.
6. Find the missing number in the sequence: 8, 14, ____, 26, 32.
20The sequence increases by 6 each step: 14 + 6 = 20.
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: 10, 14, ____, 22, 26.
18The sequence increases by 4 each step: 14 + 4 = 18.
9. Find the missing number in the sequence: 13, 22, ____, 40, 49.
31The sequence increases by 9 each step: 22 + 9 = 31.
10. Find the missing number in the sequence: 10, 13, ____, 19, 22.
16The sequence increases by 3 each step: 13 + 3 = 16.
11. Find the missing number in the sequence: 16, 25, ____, 43, 52.
34The sequence increases by 9 each step: 25 + 9 = 34.
12. Find the missing number in the sequence: 11, 15, ____, 23, 27.
19The sequence increases by 4 each step: 15 + 4 = 19.
12 questions · Seed 70 · 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: 12, 18, ____, 30, 36.
2. Find the missing number in the sequence: 15, 19, ____, 27, 31.
3. Find the missing number in the sequence: 1, 4, ____, 10, 13.
4. Find the missing number in the sequence: 12, 15, ____, 21, 24.
5. Find the missing number in the sequence: 1, 7, ____, 19, 25.
6. Find the missing number in the sequence: 8, 14, ____, 26, 32.
7. Find the missing number in the sequence: 2, 11, ____, 29, 38.
8. Find the missing number in the sequence: 10, 14, ____, 22, 26.
9. Find the missing number in the sequence: 13, 22, ____, 40, 49.
10. Find the missing number in the sequence: 10, 13, ____, 19, 22.
11. Find the missing number in the sequence: 16, 25, ____, 43, 52.
12. Find the missing number in the sequence: 11, 15, ____, 23, 27.
12 questions · Seed 70 · 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: 12, 18, ____, 30, 36.
24The sequence increases by 6 each step: 18 + 6 = 24.
2. Find the missing number in the sequence: 15, 19, ____, 27, 31.
23The sequence increases by 4 each step: 19 + 4 = 23.
3. Find the missing number in the sequence: 1, 4, ____, 10, 13.
7The sequence increases by 3 each step: 4 + 3 = 7.
4. Find the missing number in the sequence: 12, 15, ____, 21, 24.
18The sequence increases by 3 each step: 15 + 3 = 18.
5. Find the missing number in the sequence: 1, 7, ____, 19, 25.
13The sequence increases by 6 each step: 7 + 6 = 13.
6. Find the missing number in the sequence: 8, 14, ____, 26, 32.
20The sequence increases by 6 each step: 14 + 6 = 20.
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: 10, 14, ____, 22, 26.
18The sequence increases by 4 each step: 14 + 4 = 18.
9. Find the missing number in the sequence: 13, 22, ____, 40, 49.
31The sequence increases by 9 each step: 22 + 9 = 31.
10. Find the missing number in the sequence: 10, 13, ____, 19, 22.
16The sequence increases by 3 each step: 13 + 3 = 16.
11. Find the missing number in the sequence: 16, 25, ____, 43, 52.
34The sequence increases by 9 each step: 25 + 9 = 34.
12. Find the missing number in the sequence: 11, 15, ____, 23, 27.
19The sequence increases by 4 each step: 15 + 4 = 19.
12 questions · Seed 70 · Age guidance, not curriculum certification