Addition within 10 — Answer Key
Part A: Multiple Choice
Circle the correct answer for each question.
1. Mia has 5 crayons. She finds some more and now has 10. How many did she find?
A) 3
B) 4
C) 5
D) 6
C is correct because 5 + 5 = 10.
2. Which addition sentence is NOT equal to 7?
A) 3 + 4
B) 5 + 2
C) 6 + 2
D) 1 + 6
C is correct because 6 + 2 = 8, not 7, while all other choices equal 7.
3. Which pair of numbers adds up to 10?
A) 4 + 5
B) 6 + 4
C) 3 + 6
D) 5 + 4
B is correct because 6 + 4 = 10, while the other choices equal 9.
4. Ben has 3 toy cars. He gets 6 more. How many does he have in all?
A) 8
B) 9
C) 10
D) 7
B is correct because 3 + 6 = 9.
Part B: Fill in the Missing Number
Find the missing number. Write it on the line.
1. 2 + 8 = 10
To find the missing number, subtract 8 from 10: 10 - 8 = 2, so 2 + 8 = 10.
2. 5 + 4 = 9
To find the missing number, subtract 5 from 9: 9 - 5 = 4, so 5 + 4 = 9.
3. 6 + 2 = 8
To find the missing number, subtract 2 from 8: 8 - 2 = 6, so 6 + 2 = 8.
4. 3 + 7 = 10
To find the missing number, subtract 3 from 10: 10 - 3 = 7, so 3 + 7 = 10.
5. 2 + 4 = 6
To find the missing number, subtract 4 from 6: 6 - 4 = 2, so 2 + 4 = 6.