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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: 10, 13, ____, 19, 22.
2. Find the missing number in the sequence: 19, 23, ____, 31, 35.
3. Find the missing number in the sequence: 17, 26, ____, 44, 53.
4. Find the missing number in the sequence: 6, 10, ____, 18, 22.
5. Find the missing number in the sequence: 20, 24, ____, 32, 36.
6. Find the missing number in the sequence: 4, 12, ____, 28, 36.
7. Find the missing number in the sequence: 2, 8, ____, 20, 26.
8. Find the missing number in the sequence: 18, 27, ____, 45, 54.
9. Find the missing number in the sequence: 18, 21, ____, 27, 30.
10. Find the missing number in the sequence: 3, 7, ____, 15, 19.
11. Find the missing number in the sequence: 11, 18, ____, 32, 39.
12. Find the missing number in the sequence: 13, 23, ____, 43, 53.
12 questions · Seed 50 · 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: 10, 13, ____, 19, 22.
16The sequence increases by 3 each step: 13 + 3 = 16.
2. Find the missing number in the sequence: 19, 23, ____, 31, 35.
27The sequence increases by 4 each step: 23 + 4 = 27.
3. Find the missing number in the sequence: 17, 26, ____, 44, 53.
35The sequence increases by 9 each step: 26 + 9 = 35.
4. Find the missing number in the sequence: 6, 10, ____, 18, 22.
14The sequence increases by 4 each step: 10 + 4 = 14.
5. Find the missing number in the sequence: 20, 24, ____, 32, 36.
28The sequence increases by 4 each step: 24 + 4 = 28.
6. Find the missing number in the sequence: 4, 12, ____, 28, 36.
20The sequence increases by 8 each step: 12 + 8 = 20.
7. Find the missing number in the sequence: 2, 8, ____, 20, 26.
14The sequence increases by 6 each step: 8 + 6 = 14.
8. Find the missing number in the sequence: 18, 27, ____, 45, 54.
36The sequence increases by 9 each step: 27 + 9 = 36.
9. Find the missing number in the sequence: 18, 21, ____, 27, 30.
24The sequence increases by 3 each step: 21 + 3 = 24.
10. Find the missing number in the sequence: 3, 7, ____, 15, 19.
11The sequence increases by 4 each step: 7 + 4 = 11.
11. Find the missing number in the sequence: 11, 18, ____, 32, 39.
25The sequence increases by 7 each step: 18 + 7 = 25.
12. Find the missing number in the sequence: 13, 23, ____, 43, 53.
33The sequence increases by 10 each step: 23 + 10 = 33.
12 questions · Seed 50 · 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: 10, 13, ____, 19, 22.
2. Find the missing number in the sequence: 19, 23, ____, 31, 35.
3. Find the missing number in the sequence: 17, 26, ____, 44, 53.
4. Find the missing number in the sequence: 6, 10, ____, 18, 22.
5. Find the missing number in the sequence: 20, 24, ____, 32, 36.
6. Find the missing number in the sequence: 4, 12, ____, 28, 36.
7. Find the missing number in the sequence: 2, 8, ____, 20, 26.
8. Find the missing number in the sequence: 18, 27, ____, 45, 54.
9. Find the missing number in the sequence: 18, 21, ____, 27, 30.
10. Find the missing number in the sequence: 3, 7, ____, 15, 19.
11. Find the missing number in the sequence: 11, 18, ____, 32, 39.
12. Find the missing number in the sequence: 13, 23, ____, 43, 53.
12 questions · Seed 50 · 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: 10, 13, ____, 19, 22.
16The sequence increases by 3 each step: 13 + 3 = 16.
2. Find the missing number in the sequence: 19, 23, ____, 31, 35.
27The sequence increases by 4 each step: 23 + 4 = 27.
3. Find the missing number in the sequence: 17, 26, ____, 44, 53.
35The sequence increases by 9 each step: 26 + 9 = 35.
4. Find the missing number in the sequence: 6, 10, ____, 18, 22.
14The sequence increases by 4 each step: 10 + 4 = 14.
5. Find the missing number in the sequence: 20, 24, ____, 32, 36.
28The sequence increases by 4 each step: 24 + 4 = 28.
6. Find the missing number in the sequence: 4, 12, ____, 28, 36.
20The sequence increases by 8 each step: 12 + 8 = 20.
7. Find the missing number in the sequence: 2, 8, ____, 20, 26.
14The sequence increases by 6 each step: 8 + 6 = 14.
8. Find the missing number in the sequence: 18, 27, ____, 45, 54.
36The sequence increases by 9 each step: 27 + 9 = 36.
9. Find the missing number in the sequence: 18, 21, ____, 27, 30.
24The sequence increases by 3 each step: 21 + 3 = 24.
10. Find the missing number in the sequence: 3, 7, ____, 15, 19.
11The sequence increases by 4 each step: 7 + 4 = 11.
11. Find the missing number in the sequence: 11, 18, ____, 32, 39.
25The sequence increases by 7 each step: 18 + 7 = 25.
12. Find the missing number in the sequence: 13, 23, ____, 43, 53.
33The sequence increases by 10 each step: 23 + 10 = 33.
12 questions · Seed 50 · Age guidance, not curriculum certification