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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: 19, 20, ____, 22, 23.
2. Find the missing number in the sequence: 4, 5, ____, 7, 8.
3. Find the missing number in the sequence: 12, 13, ____, 15, 16.
4. Find the missing number in the sequence: 20, 25, ____, 35, 40.
5. Find the missing number in the sequence: 20, 21, ____, 23, 24.
6. Find the missing number in the sequence: 2, 4, ____, 8, 10.
7. Find the missing number in the sequence: 18, 20, ____, 24, 26.
8. Find the missing number in the sequence: 16, 21, ____, 31, 36.
9. Find the missing number in the sequence: 9, 11, ____, 15, 17.
10. Find the missing number in the sequence: 16, 17, ____, 19, 20.
11. Find the missing number in the sequence: 4, 9, ____, 19, 24.
12. Find the missing number in the sequence: 14, 15, ____, 17, 18.
12 questions · Seed 51 · 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: 19, 20, ____, 22, 23.
21The sequence increases by 1 each step: 20 + 1 = 21.
2. Find the missing number in the sequence: 4, 5, ____, 7, 8.
6The sequence increases by 1 each step: 5 + 1 = 6.
3. Find the missing number in the sequence: 12, 13, ____, 15, 16.
14The sequence increases by 1 each step: 13 + 1 = 14.
4. Find the missing number in the sequence: 20, 25, ____, 35, 40.
30The sequence increases by 5 each step: 25 + 5 = 30.
5. Find the missing number in the sequence: 20, 21, ____, 23, 24.
22The sequence increases by 1 each step: 21 + 1 = 22.
6. Find the missing number in the sequence: 2, 4, ____, 8, 10.
6The sequence increases by 2 each step: 4 + 2 = 6.
7. Find the missing number in the sequence: 18, 20, ____, 24, 26.
22The sequence increases by 2 each step: 20 + 2 = 22.
8. Find the missing number in the sequence: 16, 21, ____, 31, 36.
26The sequence increases by 5 each step: 21 + 5 = 26.
9. Find the missing number in the sequence: 9, 11, ____, 15, 17.
13The sequence increases by 2 each step: 11 + 2 = 13.
10. Find the missing number in the sequence: 16, 17, ____, 19, 20.
18The sequence increases by 1 each step: 17 + 1 = 18.
11. Find the missing number in the sequence: 4, 9, ____, 19, 24.
14The sequence increases by 5 each step: 9 + 5 = 14.
12. Find the missing number in the sequence: 14, 15, ____, 17, 18.
16The sequence increases by 1 each step: 15 + 1 = 16.
12 questions · Seed 51 · 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: 19, 20, ____, 22, 23.
2. Find the missing number in the sequence: 4, 5, ____, 7, 8.
3. Find the missing number in the sequence: 12, 13, ____, 15, 16.
4. Find the missing number in the sequence: 20, 25, ____, 35, 40.
5. Find the missing number in the sequence: 20, 21, ____, 23, 24.
6. Find the missing number in the sequence: 2, 4, ____, 8, 10.
7. Find the missing number in the sequence: 18, 20, ____, 24, 26.
8. Find the missing number in the sequence: 16, 21, ____, 31, 36.
9. Find the missing number in the sequence: 9, 11, ____, 15, 17.
10. Find the missing number in the sequence: 16, 17, ____, 19, 20.
11. Find the missing number in the sequence: 4, 9, ____, 19, 24.
12. Find the missing number in the sequence: 14, 15, ____, 17, 18.
12 questions · Seed 51 · 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: 19, 20, ____, 22, 23.
21The sequence increases by 1 each step: 20 + 1 = 21.
2. Find the missing number in the sequence: 4, 5, ____, 7, 8.
6The sequence increases by 1 each step: 5 + 1 = 6.
3. Find the missing number in the sequence: 12, 13, ____, 15, 16.
14The sequence increases by 1 each step: 13 + 1 = 14.
4. Find the missing number in the sequence: 20, 25, ____, 35, 40.
30The sequence increases by 5 each step: 25 + 5 = 30.
5. Find the missing number in the sequence: 20, 21, ____, 23, 24.
22The sequence increases by 1 each step: 21 + 1 = 22.
6. Find the missing number in the sequence: 2, 4, ____, 8, 10.
6The sequence increases by 2 each step: 4 + 2 = 6.
7. Find the missing number in the sequence: 18, 20, ____, 24, 26.
22The sequence increases by 2 each step: 20 + 2 = 22.
8. Find the missing number in the sequence: 16, 21, ____, 31, 36.
26The sequence increases by 5 each step: 21 + 5 = 26.
9. Find the missing number in the sequence: 9, 11, ____, 15, 17.
13The sequence increases by 2 each step: 11 + 2 = 13.
10. Find the missing number in the sequence: 16, 17, ____, 19, 20.
18The sequence increases by 1 each step: 17 + 1 = 18.
11. Find the missing number in the sequence: 4, 9, ____, 19, 24.
14The sequence increases by 5 each step: 9 + 5 = 14.
12. Find the missing number in the sequence: 14, 15, ____, 17, 18.
16The sequence increases by 1 each step: 15 + 1 = 16.
12 questions · Seed 51 · Age guidance, not curriculum certification