Addition Within 20 (Number Lines) — Answer Key
Part A: Multiple Choice
Circle the best answer for each question.
1. Lily has 9 crayons. She finds 4 more in her desk. How many crayons does Lily have?
A) 12
B) 14
C) 11
D) 13
Lily had 9 crayons and found 4 more, so you add 9 + 4. Jump 4 spaces from 9 on the number line to reach 13.
2. Jake counts 8 ants on the ground. Then he sees 5 more. How many ants does Jake count?
A) 14
B) 12
C) 13
D) 11
Jake saw 8 ants first and then 5 more, so 8 + 5 = 13. Start at 8 and count up 5 to check.
3. Emma reads 6 pages before lunch and 9 after lunch. How many pages does Emma read?
A) 16
B) 14
C) 15
D) 13
Emma read 6 pages and then 9 pages, so you add 6 + 9. Jumping 9 from 6 on the number line gives 15.
4. Noah has 7 grapes. His mom gives him 7 more. How many grapes does Noah have now?
A) 15
B) 13
C) 12
D) 14
Noah got the same amount he started with, so 7 + 7 is a double. Two groups of 7 make 14.
Part B: Fill in the Blank
Write the correct answer on each line.
1. 6 + 6 = 12
6 + 6 is a double. Two groups of 6 equal 12. Jump 6 from 6 on the number line to check.
2. 8 + 7 = 15
Start at 8 on the number line and jump forward 7 spaces. You pass 10 and land on 15.
3. 9 + 5 = 14
From 9, hop 1 to reach 10 and then 4 more to reach 14. Breaking it into steps makes it easier.
4. 7 + 9 = 16
Start at 7 and count forward 9 spaces on the number line to land on 16.
5. 8 + 3 = 11
From 8, jump just 3 spaces: 9, 10, 11. You reach 11 quickly because you only add a small number.