Addition Within 10 — Answer Key
Part A: Fill in the Blank
Write the missing word or number on each line.
1. 7 + 3 = 10
Think: 7 plus what number makes 9? Count up from 7 to 9 and you count 2 more.
2. 4 + 5 = 9
Think: what number plus 3 makes 8? Since 5 + 3 = 8, the missing number is 5.
3. 2 + 8 = 10
Think: 2 plus what number makes 10? Count up from 2 to 10 and you count 8 more.
4. 6 + 1 = 7
Think: what number plus 6 makes 7? Since 1 + 6 = 7, the missing number is 1.
5. 2 + 1 = 3
Think: 5 plus what number makes 8? Count up from 5 to 8 and you count 3 more.
6. 4 + 2 = 6
Think: what number plus 0 makes 9? Since 9 + 0 = 9, the missing number is 9.
7. 3 + 2 = 5
Think: 1 plus what number makes 4? Count up from 1 to 4 and you count 3 more.
8. 2 + 6 = 8
Think: what number plus 5 makes 10? Since 5 + 5 = 10, the missing number is 5.
9. 1 + 1 = 2
Think: 3 plus what number makes 7? Count up from 3 to 7 and you count 4 more.
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 addition fact matches its correct sum. 5 + 1 = 6, 3 + 2 = 5, 7 + 3 = 10, 4 + 4 = 8.