Addition Within 10 — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. 7 + 3 = 10
Since 7 + 3 = 10, the missing number is 3.
2. 4 + 5 = 9
Since 4 + 5 = 9, the missing number is 4.
3. 2 + 8 = 10
Counting on from 2 by 8 more makes a ten, so 2 + 8 = 10.
4. 6 + 1 = 7
Since 6 + 1 = 7, the missing number is 1.
5. 2 + 1 = 3
Since 2 + 1 = 3, the missing number is 2.
6. 4 + 2 = 6
Joining 4 and 2 makes a group of 6, so 4 + 2 = 6.
7. 3 + 2 = 5
Since 3 + 2 = 5, the missing number is 2.
8. 2 + 6 = 8
Since 2 + 6 = 8, the missing number is 2.
9. 1 + 1 = 2
Doubling 1 gives 2, because 1 + 1 = 2.
Part B: Matching
Match each item on the left to the correct answer on the right.
1. Match each item to its correct answer.
4 + 1
→ 5
8
6 + 3
→ 9
5
2 + 6
→ 8
4
0 + 4
→ 4
9
Each fact matches its total: 4 + 1 makes 5, 6 + 3 makes 9, 2 + 6 makes 8, and 0 + 4 stays 4 because adding zero changes nothing.