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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 4-6
Missing sequence terms
Take your time. Show your thinking.
1. Find the missing number in the sequence: 20, 21, ____, 23, 24.
2. Find the missing number in the sequence: 11, 13, ____, 17, 19.
3. Find the missing number in the sequence: 9, 10, ____, 12, 13.
4. Find the missing number in the sequence: 15, 16, ____, 18, 19.
5. Find the missing number in the sequence: 4, 6, ____, 10, 12.
6. Find the missing number in the sequence: 14, 15, ____, 17, 18.
7. Find the missing number in the sequence: 11, 16, ____, 26, 31.
8. Find the missing number in the sequence: 6, 11, ____, 21, 26.
9. Find the missing number in the sequence: 2, 7, ____, 17, 22.
10. Find the missing number in the sequence: 15, 17, ____, 21, 23.
11. Find the missing number in the sequence: 13, 14, ____, 16, 17.
12. Find the missing number in the sequence: 12, 14, ____, 18, 20.
12 questions · Seed 79 · Age guidance, not curriculum certification
View the answer key
Worksheet StudioAnswer key · Ages 4-6
Missing sequence terms
Answers and reasoning. Review before teaching.
1. Find the missing number in the sequence: 20, 21, ____, 23, 24.
22The sequence increases by 1 each step: 21 + 1 = 22.
2. Find the missing number in the sequence: 11, 13, ____, 17, 19.
15The sequence increases by 2 each step: 13 + 2 = 15.
3. Find the missing number in the sequence: 9, 10, ____, 12, 13.
11The sequence increases by 1 each step: 10 + 1 = 11.
4. Find the missing number in the sequence: 15, 16, ____, 18, 19.
17The sequence increases by 1 each step: 16 + 1 = 17.
5. Find the missing number in the sequence: 4, 6, ____, 10, 12.
8The sequence increases by 2 each step: 6 + 2 = 8.
6. Find the missing number in the sequence: 14, 15, ____, 17, 18.
16The sequence increases by 1 each step: 15 + 1 = 16.
7. Find the missing number in the sequence: 11, 16, ____, 26, 31.
21The sequence increases by 5 each step: 16 + 5 = 21.
8. Find the missing number in the sequence: 6, 11, ____, 21, 26.
16The sequence increases by 5 each step: 11 + 5 = 16.
9. Find the missing number in the sequence: 2, 7, ____, 17, 22.
12The sequence increases by 5 each step: 7 + 5 = 12.
10. Find the missing number in the sequence: 15, 17, ____, 21, 23.
19The sequence increases by 2 each step: 17 + 2 = 19.
11. Find the missing number in the sequence: 13, 14, ____, 16, 17.
15The sequence increases by 1 each step: 14 + 1 = 15.
12. Find the missing number in the sequence: 12, 14, ____, 18, 20.
16The sequence increases by 2 each step: 14 + 2 = 16.
12 questions · Seed 79 · Age guidance, not curriculum certification
Worksheet StudioPractice pack · Ages 4-6
Missing sequence terms
Take your time. Show your thinking.
1. Find the missing number in the sequence: 20, 21, ____, 23, 24.
2. Find the missing number in the sequence: 11, 13, ____, 17, 19.
3. Find the missing number in the sequence: 9, 10, ____, 12, 13.
4. Find the missing number in the sequence: 15, 16, ____, 18, 19.
5. Find the missing number in the sequence: 4, 6, ____, 10, 12.
6. Find the missing number in the sequence: 14, 15, ____, 17, 18.
7. Find the missing number in the sequence: 11, 16, ____, 26, 31.
8. Find the missing number in the sequence: 6, 11, ____, 21, 26.
9. Find the missing number in the sequence: 2, 7, ____, 17, 22.
10. Find the missing number in the sequence: 15, 17, ____, 21, 23.
11. Find the missing number in the sequence: 13, 14, ____, 16, 17.
12. Find the missing number in the sequence: 12, 14, ____, 18, 20.
12 questions · Seed 79 · Age guidance, not curriculum certification
Worksheet StudioAnswer key · Ages 4-6
Missing sequence terms
Answers and reasoning. Review before teaching.
1. Find the missing number in the sequence: 20, 21, ____, 23, 24.
22The sequence increases by 1 each step: 21 + 1 = 22.
2. Find the missing number in the sequence: 11, 13, ____, 17, 19.
15The sequence increases by 2 each step: 13 + 2 = 15.
3. Find the missing number in the sequence: 9, 10, ____, 12, 13.
11The sequence increases by 1 each step: 10 + 1 = 11.
4. Find the missing number in the sequence: 15, 16, ____, 18, 19.
17The sequence increases by 1 each step: 16 + 1 = 17.
5. Find the missing number in the sequence: 4, 6, ____, 10, 12.
8The sequence increases by 2 each step: 6 + 2 = 8.
6. Find the missing number in the sequence: 14, 15, ____, 17, 18.
16The sequence increases by 1 each step: 15 + 1 = 16.
7. Find the missing number in the sequence: 11, 16, ____, 26, 31.
21The sequence increases by 5 each step: 16 + 5 = 21.
8. Find the missing number in the sequence: 6, 11, ____, 21, 26.
16The sequence increases by 5 each step: 11 + 5 = 16.
9. Find the missing number in the sequence: 2, 7, ____, 17, 22.
12The sequence increases by 5 each step: 7 + 5 = 12.
10. Find the missing number in the sequence: 15, 17, ____, 21, 23.
19The sequence increases by 2 each step: 17 + 2 = 19.
11. Find the missing number in the sequence: 13, 14, ____, 16, 17.
15The sequence increases by 1 each step: 14 + 1 = 15.
12. Find the missing number in the sequence: 12, 14, ____, 18, 20.
16The sequence increases by 2 each step: 14 + 2 = 16.
12 questions · Seed 79 · Age guidance, not curriculum certification