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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: 19, 23, ____, 31, 35.
2. Find the missing number in the sequence: 7, 14, ____, 28, 35.
3. Find the missing number in the sequence: 11, 15, ____, 23, 27.
4. Find the missing number in the sequence: 7, 17, ____, 37, 47.
5. Find the missing number in the sequence: 5, 8, ____, 14, 17.
6. Find the missing number in the sequence: 13, 23, ____, 43, 53.
7. Find the missing number in the sequence: 13, 19, ____, 31, 37.
8. Find the missing number in the sequence: 5, 9, ____, 17, 21.
9. Find the missing number in the sequence: 20, 26, ____, 38, 44.
10. Find the missing number in the sequence: 9, 15, ____, 27, 33.
11. Find the missing number in the sequence: 5, 12, ____, 26, 33.
12. Find the missing number in the sequence: 9, 13, ____, 21, 25.
12 questions · Seed 103 · 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: 19, 23, ____, 31, 35.
27The sequence increases by 4 each step: 23 + 4 = 27.
2. Find the missing number in the sequence: 7, 14, ____, 28, 35.
21The sequence increases by 7 each step: 14 + 7 = 21.
3. Find the missing number in the sequence: 11, 15, ____, 23, 27.
19The sequence increases by 4 each step: 15 + 4 = 19.
4. Find the missing number in the sequence: 7, 17, ____, 37, 47.
27The sequence increases by 10 each step: 17 + 10 = 27.
5. Find the missing number in the sequence: 5, 8, ____, 14, 17.
11The sequence increases by 3 each step: 8 + 3 = 11.
6. Find the missing number in the sequence: 13, 23, ____, 43, 53.
33The sequence increases by 10 each step: 23 + 10 = 33.
7. Find the missing number in the sequence: 13, 19, ____, 31, 37.
25The sequence increases by 6 each step: 19 + 6 = 25.
8. Find the missing number in the sequence: 5, 9, ____, 17, 21.
13The sequence increases by 4 each step: 9 + 4 = 13.
9. Find the missing number in the sequence: 20, 26, ____, 38, 44.
32The sequence increases by 6 each step: 26 + 6 = 32.
10. Find the missing number in the sequence: 9, 15, ____, 27, 33.
21The sequence increases by 6 each step: 15 + 6 = 21.
11. Find the missing number in the sequence: 5, 12, ____, 26, 33.
19The sequence increases by 7 each step: 12 + 7 = 19.
12. Find the missing number in the sequence: 9, 13, ____, 21, 25.
17The sequence increases by 4 each step: 13 + 4 = 17.
12 questions · Seed 103 · 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: 19, 23, ____, 31, 35.
2. Find the missing number in the sequence: 7, 14, ____, 28, 35.
3. Find the missing number in the sequence: 11, 15, ____, 23, 27.
4. Find the missing number in the sequence: 7, 17, ____, 37, 47.
5. Find the missing number in the sequence: 5, 8, ____, 14, 17.
6. Find the missing number in the sequence: 13, 23, ____, 43, 53.
7. Find the missing number in the sequence: 13, 19, ____, 31, 37.
8. Find the missing number in the sequence: 5, 9, ____, 17, 21.
9. Find the missing number in the sequence: 20, 26, ____, 38, 44.
10. Find the missing number in the sequence: 9, 15, ____, 27, 33.
11. Find the missing number in the sequence: 5, 12, ____, 26, 33.
12. Find the missing number in the sequence: 9, 13, ____, 21, 25.
12 questions · Seed 103 · 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: 19, 23, ____, 31, 35.
27The sequence increases by 4 each step: 23 + 4 = 27.
2. Find the missing number in the sequence: 7, 14, ____, 28, 35.
21The sequence increases by 7 each step: 14 + 7 = 21.
3. Find the missing number in the sequence: 11, 15, ____, 23, 27.
19The sequence increases by 4 each step: 15 + 4 = 19.
4. Find the missing number in the sequence: 7, 17, ____, 37, 47.
27The sequence increases by 10 each step: 17 + 10 = 27.
5. Find the missing number in the sequence: 5, 8, ____, 14, 17.
11The sequence increases by 3 each step: 8 + 3 = 11.
6. Find the missing number in the sequence: 13, 23, ____, 43, 53.
33The sequence increases by 10 each step: 23 + 10 = 33.
7. Find the missing number in the sequence: 13, 19, ____, 31, 37.
25The sequence increases by 6 each step: 19 + 6 = 25.
8. Find the missing number in the sequence: 5, 9, ____, 17, 21.
13The sequence increases by 4 each step: 9 + 4 = 13.
9. Find the missing number in the sequence: 20, 26, ____, 38, 44.
32The sequence increases by 6 each step: 26 + 6 = 32.
10. Find the missing number in the sequence: 9, 15, ____, 27, 33.
21The sequence increases by 6 each step: 15 + 6 = 21.
11. Find the missing number in the sequence: 5, 12, ____, 26, 33.
19The sequence increases by 7 each step: 12 + 7 = 19.
12. Find the missing number in the sequence: 9, 13, ____, 21, 25.
17The sequence increases by 4 each step: 13 + 4 = 17.
12 questions · Seed 103 · Age guidance, not curriculum certification