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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: 4, 12, ____, 28, 36.
2. Find the missing number in the sequence: 15, 24, ____, 42, 51.
3. Find the missing number in the sequence: 10, 14, ____, 22, 26.
4. Find the missing number in the sequence: 10, 13, ____, 19, 22.
5. Find the missing number in the sequence: 7, 16, ____, 34, 43.
6. Find the missing number in the sequence: 1, 8, ____, 22, 29.
7. Find the missing number in the sequence: 9, 18, ____, 36, 45.
8. Find the missing number in the sequence: 12, 20, ____, 36, 44.
9. Find the missing number in the sequence: 20, 23, ____, 29, 32.
10. Find the missing number in the sequence: 19, 29, ____, 49, 59.
11. Find the missing number in the sequence: 15, 22, ____, 36, 43.
12. Find the missing number in the sequence: 4, 13, ____, 31, 40.
12 questions · Seed 66 · 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: 4, 12, ____, 28, 36.
20The sequence increases by 8 each step: 12 + 8 = 20.
2. Find the missing number in the sequence: 15, 24, ____, 42, 51.
33The sequence increases by 9 each step: 24 + 9 = 33.
3. Find the missing number in the sequence: 10, 14, ____, 22, 26.
18The sequence increases by 4 each step: 14 + 4 = 18.
4. Find the missing number in the sequence: 10, 13, ____, 19, 22.
16The sequence increases by 3 each step: 13 + 3 = 16.
5. Find the missing number in the sequence: 7, 16, ____, 34, 43.
25The sequence increases by 9 each step: 16 + 9 = 25.
6. Find the missing number in the sequence: 1, 8, ____, 22, 29.
15The sequence increases by 7 each step: 8 + 7 = 15.
7. Find the missing number in the sequence: 9, 18, ____, 36, 45.
27The sequence increases by 9 each step: 18 + 9 = 27.
8. Find the missing number in the sequence: 12, 20, ____, 36, 44.
28The sequence increases by 8 each step: 20 + 8 = 28.
9. Find the missing number in the sequence: 20, 23, ____, 29, 32.
26The sequence increases by 3 each step: 23 + 3 = 26.
10. Find the missing number in the sequence: 19, 29, ____, 49, 59.
39The sequence increases by 10 each step: 29 + 10 = 39.
11. Find the missing number in the sequence: 15, 22, ____, 36, 43.
29The sequence increases by 7 each step: 22 + 7 = 29.
12. Find the missing number in the sequence: 4, 13, ____, 31, 40.
22The sequence increases by 9 each step: 13 + 9 = 22.
12 questions · Seed 66 · 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: 4, 12, ____, 28, 36.
2. Find the missing number in the sequence: 15, 24, ____, 42, 51.
3. Find the missing number in the sequence: 10, 14, ____, 22, 26.
4. Find the missing number in the sequence: 10, 13, ____, 19, 22.
5. Find the missing number in the sequence: 7, 16, ____, 34, 43.
6. Find the missing number in the sequence: 1, 8, ____, 22, 29.
7. Find the missing number in the sequence: 9, 18, ____, 36, 45.
8. Find the missing number in the sequence: 12, 20, ____, 36, 44.
9. Find the missing number in the sequence: 20, 23, ____, 29, 32.
10. Find the missing number in the sequence: 19, 29, ____, 49, 59.
11. Find the missing number in the sequence: 15, 22, ____, 36, 43.
12. Find the missing number in the sequence: 4, 13, ____, 31, 40.
12 questions · Seed 66 · 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: 4, 12, ____, 28, 36.
20The sequence increases by 8 each step: 12 + 8 = 20.
2. Find the missing number in the sequence: 15, 24, ____, 42, 51.
33The sequence increases by 9 each step: 24 + 9 = 33.
3. Find the missing number in the sequence: 10, 14, ____, 22, 26.
18The sequence increases by 4 each step: 14 + 4 = 18.
4. Find the missing number in the sequence: 10, 13, ____, 19, 22.
16The sequence increases by 3 each step: 13 + 3 = 16.
5. Find the missing number in the sequence: 7, 16, ____, 34, 43.
25The sequence increases by 9 each step: 16 + 9 = 25.
6. Find the missing number in the sequence: 1, 8, ____, 22, 29.
15The sequence increases by 7 each step: 8 + 7 = 15.
7. Find the missing number in the sequence: 9, 18, ____, 36, 45.
27The sequence increases by 9 each step: 18 + 9 = 27.
8. Find the missing number in the sequence: 12, 20, ____, 36, 44.
28The sequence increases by 8 each step: 20 + 8 = 28.
9. Find the missing number in the sequence: 20, 23, ____, 29, 32.
26The sequence increases by 3 each step: 23 + 3 = 26.
10. Find the missing number in the sequence: 19, 29, ____, 49, 59.
39The sequence increases by 10 each step: 29 + 10 = 39.
11. Find the missing number in the sequence: 15, 22, ____, 36, 43.
29The sequence increases by 7 each step: 22 + 7 = 29.
12. Find the missing number in the sequence: 4, 13, ____, 31, 40.
22The sequence increases by 9 each step: 13 + 9 = 22.
12 questions · Seed 66 · Age guidance, not curriculum certification