Addition Within 20 (Number Lines) — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. Mia has 8 stickers. She gets 7 more. How many stickers does Mia have now?
A) 14
B) 15
C) 16
D) 13
Mia had 8 stickers and got 7 more, so you add 8 + 7. Start at 8 on the number line and jump 7 to get 15.
2. Ben sees 9 birds on a fence. Then 6 more land. How many birds are on the fence?
A) 16
B) 14
C) 15
D) 13
Ben saw 9 birds and 6 more joined, so you add 9 + 6. Jumping 6 from 9 on the number line gives 15.
3. Sara picks 7 flowers. Then she picks 9 more. How many flowers does Sara have?
A) 15
B) 17
C) 16
D) 14
Sara picked 7 first and then 9 more, so you add 7 + 9. Counting forward 9 from 7 lands on 16.
4. Tom has 6 toy cars. His friend gives him 8 more. How many does Tom have now?
A) 15
B) 13
C) 12
D) 14
Tom started with 6 cars and added 8 more, so 6 + 8 = 14. Jump 8 spaces from 6 on the number line to check.
Part B: Fill in the Blank
Write the correct answer on each line.
1. 9 + 8 = 17
Start at 9 and hop 8 spaces forward on the number line. You pass 10 and keep going until you reach 17.
2. 7 + 6 = 13
From 7, count up 6 more: 8, 9, 10, 11, 12, 13. The number line shows you land on 13.
3. 8 + 8 = 16
8 + 8 is a double. Two groups of 8 make 16. On the number line, jump 8 from 8 to reach 16.
4. 5 + 7 = 12
Start at 5 and jump forward 7 spaces: 6, 7, 8, 9, 10, 11, 12. You land on 12.
5. 9 + 9 = 18
9 + 9 is the biggest double within 20. Two groups of 9 equal 18.