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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: 3, 6, ____, 12, 15.
2. Find the missing number in the sequence: 19, 27, ____, 43, 51.
3. Find the missing number in the sequence: 10, 20, ____, 40, 50.
4. Find the missing number in the sequence: 18, 27, ____, 45, 54.
5. Find the missing number in the sequence: 14, 17, ____, 23, 26.
6. Find the missing number in the sequence: 17, 25, ____, 41, 49.
7. Find the missing number in the sequence: 14, 21, ____, 35, 42.
8. Find the missing number in the sequence: 11, 15, ____, 23, 27.
9. Find the missing number in the sequence: 11, 20, ____, 38, 47.
10. Find the missing number in the sequence: 5, 8, ____, 14, 17.
11. Find the missing number in the sequence: 2, 9, ____, 23, 30.
12. Find the missing number in the sequence: 3, 12, ____, 30, 39.
12 questions · Seed 104740 · 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: 3, 6, ____, 12, 15.
9The sequence increases by 3 each step: 6 + 3 = 9.
2. Find the missing number in the sequence: 19, 27, ____, 43, 51.
35The sequence increases by 8 each step: 27 + 8 = 35.
3. Find the missing number in the sequence: 10, 20, ____, 40, 50.
30The sequence increases by 10 each step: 20 + 10 = 30.
4. Find the missing number in the sequence: 18, 27, ____, 45, 54.
36The sequence increases by 9 each step: 27 + 9 = 36.
5. Find the missing number in the sequence: 14, 17, ____, 23, 26.
20The sequence increases by 3 each step: 17 + 3 = 20.
6. Find the missing number in the sequence: 17, 25, ____, 41, 49.
33The sequence increases by 8 each step: 25 + 8 = 33.
7. Find the missing number in the sequence: 14, 21, ____, 35, 42.
28The sequence increases by 7 each step: 21 + 7 = 28.
8. Find the missing number in the sequence: 11, 15, ____, 23, 27.
19The sequence increases by 4 each step: 15 + 4 = 19.
9. Find the missing number in the sequence: 11, 20, ____, 38, 47.
29The sequence increases by 9 each step: 20 + 9 = 29.
10. Find the missing number in the sequence: 5, 8, ____, 14, 17.
11The sequence increases by 3 each step: 8 + 3 = 11.
11. Find the missing number in the sequence: 2, 9, ____, 23, 30.
16The sequence increases by 7 each step: 9 + 7 = 16.
12. Find the missing number in the sequence: 3, 12, ____, 30, 39.
21The sequence increases by 9 each step: 12 + 9 = 21.
12 questions · Seed 104740 · 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: 3, 6, ____, 12, 15.
2. Find the missing number in the sequence: 19, 27, ____, 43, 51.
3. Find the missing number in the sequence: 10, 20, ____, 40, 50.
4. Find the missing number in the sequence: 18, 27, ____, 45, 54.
5. Find the missing number in the sequence: 14, 17, ____, 23, 26.
6. Find the missing number in the sequence: 17, 25, ____, 41, 49.
7. Find the missing number in the sequence: 14, 21, ____, 35, 42.
8. Find the missing number in the sequence: 11, 15, ____, 23, 27.
9. Find the missing number in the sequence: 11, 20, ____, 38, 47.
10. Find the missing number in the sequence: 5, 8, ____, 14, 17.
11. Find the missing number in the sequence: 2, 9, ____, 23, 30.
12. Find the missing number in the sequence: 3, 12, ____, 30, 39.
12 questions · Seed 104740 · 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: 3, 6, ____, 12, 15.
9The sequence increases by 3 each step: 6 + 3 = 9.
2. Find the missing number in the sequence: 19, 27, ____, 43, 51.
35The sequence increases by 8 each step: 27 + 8 = 35.
3. Find the missing number in the sequence: 10, 20, ____, 40, 50.
30The sequence increases by 10 each step: 20 + 10 = 30.
4. Find the missing number in the sequence: 18, 27, ____, 45, 54.
36The sequence increases by 9 each step: 27 + 9 = 36.
5. Find the missing number in the sequence: 14, 17, ____, 23, 26.
20The sequence increases by 3 each step: 17 + 3 = 20.
6. Find the missing number in the sequence: 17, 25, ____, 41, 49.
33The sequence increases by 8 each step: 25 + 8 = 33.
7. Find the missing number in the sequence: 14, 21, ____, 35, 42.
28The sequence increases by 7 each step: 21 + 7 = 28.
8. Find the missing number in the sequence: 11, 15, ____, 23, 27.
19The sequence increases by 4 each step: 15 + 4 = 19.
9. Find the missing number in the sequence: 11, 20, ____, 38, 47.
29The sequence increases by 9 each step: 20 + 9 = 29.
10. Find the missing number in the sequence: 5, 8, ____, 14, 17.
11The sequence increases by 3 each step: 8 + 3 = 11.
11. Find the missing number in the sequence: 2, 9, ____, 23, 30.
16The sequence increases by 7 each step: 9 + 7 = 16.
12. Find the missing number in the sequence: 3, 12, ____, 30, 39.
21The sequence increases by 9 each step: 12 + 9 = 21.
12 questions · Seed 104740 · Age guidance, not curriculum certification