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