Addition Within 20 — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. What is 8 + 9?
A) 15
B) 16
C) 17
D) 18
Make a ten: 9 + 1 = 10, then 10 + 7 = 17.
2. What is 6 + 7?
A) 12
B) 13
C) 14
D) 15
Make a ten: 7 + 3 = 10, then 10 + 3 = 13.
3. What is 7 + 8?
A) 13
B) 14
C) 15
D) 16
Make a ten: 8 + 2 = 10, then 10 + 5 = 15.
4. What is 9 + 6?
A) 14
B) 15
C) 16
D) 17
Make a ten: 9 + 1 = 10, then 10 + 5 = 15.
Part B: Fill in the Blank
Write the correct answer on each line.
1. 9 + 5 = 14
Think: what number plus 5 equals 14? Since 9 + 5 = 14, the missing number is 9.
2. 8 + 9 = 17
Think: 8 plus what number equals 17? Since 8 + 9 = 17, the missing number is 9.
3. 6 + 7 = 13
Think: what number plus 7 equals 13? Since 6 + 7 = 13, the missing number is 6.
4. 7 + 9 = 16
Think: 7 plus what number equals 16? Since 7 + 9 = 16, the missing number is 9.
5. 8 + 8 = 16
Think: what number plus 8 equals 16? Since 8 + 8 = 16, the missing number is 8.