Count to 20 — Answer Key
Part A: Fill in the Missing Number
Write the missing number on each line.
1. The number after 9 is 10.
Counting forward from 9: the next number is 10.
2. The number before 15 is 14.
The number just before 15 is 14. The sequence is 14, 15, 16.
3. 10 + 7 = 17.
10 + 7 = 17. Teen numbers are made by adding a single digit to 10.
4. 10 + 3 = 13.
10 + 3 = 13. The teen number 13 is ten and three more.
5. The number after 19 is 20.
Counting forward from 19: the next number is 20, the last number in our count.
6. 10 + 9 = 19.
10 + 9 = 19. The teen number 19 is ten and nine more.
7. The number before 12 is 11.
The number just before 12 is 11. The sequence is 11, 12, 13.
8. 10 + 5 = 15.
10 + 5 = 15. The teen number 15 is ten and five more.
9. The number between 17 and 19 is 18.
In the sequence 17, 18, 19 — the number between 17 and 19 is 18.
Part B: Matching
Match each number sequence clue to the correct answer.
1. Draw a line to match.
Count on 2 from 14
→ 16
19
Teen number: 10 + 8
→ 18
11
The number after 10
→ 11
16
The number before 20
→ 19
18
Count on 2 from 14→16, 10+8→18, after 10→11, before 20→19.