Skip Counting — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. 3, 6, 9, 12, 15.
The pattern adds 3 each time (3, 6, 9, 12), so the next number is 12 + 3 = 15.
2. 18, 21, 24, 27, 30.
This is a count-by-3s pattern, and 21 + 3 = 24. That also works because 24 + 3 gives 27, the next number shown.
3. 10, 12, 14, 16, 18.
Each step adds 2, so the number after 14 is 14 + 2 = 16, which is also 2 less than 18.
4. 40, 45, 50, 55, 60.
The pattern jumps by 5 each time, so 50 + 5 = 55, which is exactly halfway between 50 and 60.
5. 90, 100, 110, 120, 130.
This list goes up by 10 at every step, so after 110 you get 110 + 10 = 120, which is also 10 less than 130.
6. 24, 27, 30, 33, 36.
Counting by 3s, 30 + 3 = 33. You can check it because 33 + 3 = 36, which matches the last number.
7. 20, 22, 24, 26, 28.
The numbers go up by 2, so working backward gives 22 - 2 = 20 as the first number in the count-by-2s sequence.
8. 65, 70, 75, 80, 85.
Each number is 5 bigger than the last, so 75 + 5 = 80, which is also 5 less than 85.
9. 6, 9, 12, 15, 18.
The pattern adds 3 every time (6, 9, 12, 15), so the next number is 15 + 3 = 18.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
3, 6, 9, 12, 15
→ Count by 3s
Count by 5s
20, 22, 24, 26, 28
→ Count by 2s
Count by 3s
60, 70, 80, 90, 100
→ Count by 10s
Count by 2s
25, 30, 35, 40, 45
→ Count by 5s
Count by 10s
Look at the jump between two next-door numbers to spot the pattern: 3 to 6 is a jump of 3, 20 to 22 is 2, 60 to 70 is 10, and 25 to 30 is 5, which tells you the skip-count rule for each list.