Addition Within 10 — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. Tom has some stickers. He gets 3 more and now has 10. How many did he start with?
A) 6
B) 8
C) 7
D) 5
7 + 3 = 10, so Tom began with 7 stickers. Work backward: if 3 new stickers brought the count up to 10, take those 3 away to find the starting amount.
2. Which addition sentence equals 6?
A) 2 + 5
B) 4 + 2
C) 3 + 4
D) 5 + 3
4 + 2 = 6. Count on from 4: 5, 6. The other choices land on different totals, so 4 + 2 is the one that makes 6.
3. Which pair of numbers does NOT add up to 10?
A) 8 + 2
B) 5 + 5
C) 6 + 3
D) 7 + 3
6 + 3 = 9, not 10 — 6 would need 4, not 3, to reach 10. The other pairs are all make-ten partners.
4. A bird has 1 egg in its nest. It lays 8 more. How many eggs are there now?
A) 8
B) 10
C) 7
D) 9
1 + 8 = 9. Flip it to 8 + 1 and the next number after 8 is 9 — the nest now holds 9 eggs.
Part B: Fill in the Blank
Write the correct answer on each line.
1. 1 + 9 = 10
1 + 9 = 10. 9 only needs one more to jump to 10.
2. 5 + 2 = 7
5 + 2 = 7. From 5, two steps forward land on 7.
3. 4 + 4 = 8
4 + 4 = 8. This is a doubles fact — the missing part must match the other 4 to make 8.
4. 3 + 6 = 9
3 + 6 = 9. The gap between 3 and 9 is 6, so 6 fills the blank.
5. 8 + 2 = 10
8 + 2 = 10. 8 and 2 are make-ten partners, so 8 completes the ten-frame.