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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: 18, 28, ____, 48, 58.
2. Find the missing number in the sequence: 12, 15, ____, 21, 24.
3. Find the missing number in the sequence: 16, 23, ____, 37, 44.
4. Find the missing number in the sequence: 17, 23, ____, 35, 41.
5. Find the missing number in the sequence: 9, 18, ____, 36, 45.
6. Find the missing number in the sequence: 18, 24, ____, 36, 42.
7. Find the missing number in the sequence: 6, 9, ____, 15, 18.
8. Find the missing number in the sequence: 9, 16, ____, 30, 37.
9. Find the missing number in the sequence: 19, 22, ____, 28, 31.
10. Find the missing number in the sequence: 2, 9, ____, 23, 30.
11. Find the missing number in the sequence: 9, 12, ____, 18, 21.
12. Find the missing number in the sequence: 12, 19, ____, 33, 40.
12 questions · Seed 96 · 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: 18, 28, ____, 48, 58.
38The sequence increases by 10 each step: 28 + 10 = 38.
2. Find the missing number in the sequence: 12, 15, ____, 21, 24.
18The sequence increases by 3 each step: 15 + 3 = 18.
3. Find the missing number in the sequence: 16, 23, ____, 37, 44.
30The sequence increases by 7 each step: 23 + 7 = 30.
4. Find the missing number in the sequence: 17, 23, ____, 35, 41.
29The sequence increases by 6 each step: 23 + 6 = 29.
5. Find the missing number in the sequence: 9, 18, ____, 36, 45.
27The sequence increases by 9 each step: 18 + 9 = 27.
6. Find the missing number in the sequence: 18, 24, ____, 36, 42.
30The sequence increases by 6 each step: 24 + 6 = 30.
7. Find the missing number in the sequence: 6, 9, ____, 15, 18.
12The sequence increases by 3 each step: 9 + 3 = 12.
8. Find the missing number in the sequence: 9, 16, ____, 30, 37.
23The sequence increases by 7 each step: 16 + 7 = 23.
9. Find the missing number in the sequence: 19, 22, ____, 28, 31.
25The sequence increases by 3 each step: 22 + 3 = 25.
10. Find the missing number in the sequence: 2, 9, ____, 23, 30.
16The sequence increases by 7 each step: 9 + 7 = 16.
11. Find the missing number in the sequence: 9, 12, ____, 18, 21.
15The sequence increases by 3 each step: 12 + 3 = 15.
12. Find the missing number in the sequence: 12, 19, ____, 33, 40.
26The sequence increases by 7 each step: 19 + 7 = 26.
12 questions · Seed 96 · 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: 18, 28, ____, 48, 58.
2. Find the missing number in the sequence: 12, 15, ____, 21, 24.
3. Find the missing number in the sequence: 16, 23, ____, 37, 44.
4. Find the missing number in the sequence: 17, 23, ____, 35, 41.
5. Find the missing number in the sequence: 9, 18, ____, 36, 45.
6. Find the missing number in the sequence: 18, 24, ____, 36, 42.
7. Find the missing number in the sequence: 6, 9, ____, 15, 18.
8. Find the missing number in the sequence: 9, 16, ____, 30, 37.
9. Find the missing number in the sequence: 19, 22, ____, 28, 31.
10. Find the missing number in the sequence: 2, 9, ____, 23, 30.
11. Find the missing number in the sequence: 9, 12, ____, 18, 21.
12. Find the missing number in the sequence: 12, 19, ____, 33, 40.
12 questions · Seed 96 · 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: 18, 28, ____, 48, 58.
38The sequence increases by 10 each step: 28 + 10 = 38.
2. Find the missing number in the sequence: 12, 15, ____, 21, 24.
18The sequence increases by 3 each step: 15 + 3 = 18.
3. Find the missing number in the sequence: 16, 23, ____, 37, 44.
30The sequence increases by 7 each step: 23 + 7 = 30.
4. Find the missing number in the sequence: 17, 23, ____, 35, 41.
29The sequence increases by 6 each step: 23 + 6 = 29.
5. Find the missing number in the sequence: 9, 18, ____, 36, 45.
27The sequence increases by 9 each step: 18 + 9 = 27.
6. Find the missing number in the sequence: 18, 24, ____, 36, 42.
30The sequence increases by 6 each step: 24 + 6 = 30.
7. Find the missing number in the sequence: 6, 9, ____, 15, 18.
12The sequence increases by 3 each step: 9 + 3 = 12.
8. Find the missing number in the sequence: 9, 16, ____, 30, 37.
23The sequence increases by 7 each step: 16 + 7 = 23.
9. Find the missing number in the sequence: 19, 22, ____, 28, 31.
25The sequence increases by 3 each step: 22 + 3 = 25.
10. Find the missing number in the sequence: 2, 9, ____, 23, 30.
16The sequence increases by 7 each step: 9 + 7 = 16.
11. Find the missing number in the sequence: 9, 12, ____, 18, 21.
15The sequence increases by 3 each step: 12 + 3 = 15.
12. Find the missing number in the sequence: 12, 19, ____, 33, 40.
26The sequence increases by 7 each step: 19 + 7 = 26.
12 questions · Seed 96 · Age guidance, not curriculum certification