Extra Set

Grade 7 · Unit 5 · L21 · Version A · 904F

Percent change and percent error

Name ________________

Date ________________

Period ________________

1.
A price goes from $100 to $110. What is the percent increase?
Answer. 10%
Change = 10; divide by 100 → 10%.
2.
A price goes from $40 to $60. What is the percent increase?
Answer. 50%
Change = 20; divide by 40 → 50%.
3.
A price goes from $40 to $20. What is the percent decrease?
Answer. 50%
Change = 20; divide by 40 → 50%.
4.
A price goes from $40 to $36. What is the percent decrease?
Answer. 10%
Change = 4; divide by 40 → 10%.
5.
A price goes from $80 to $96. What is the percent increase? Write a complete answer — Jonah will compare with a partner.
Answer. 20%
Change = 16; divide by 80 → 20%.
6.
A price goes from $120 to $60. What is the percent decrease? Write a complete answer — Theo will compare with a partner.
Answer. 50%
Change = 60; divide by 120 → 50%.
7.
A price goes from $100 to $75. What is the percent decrease? Write a complete answer — Sam will compare with a partner.
Answer. 25%
Change = 25; divide by 100 → 25%.
8.
A price goes from $80 to $60. What is the percent decrease? Write a complete answer — Elena will compare with a partner.
Answer. 25%
Change = 20; divide by 80 → 25%.
9.
A price goes from $80 to $88. What is the percent increase? Write a complete answer — Grace will compare with a partner.
Answer. 10%
Change = 8; divide by 80 → 10%.
10.
A price goes from $50 to $55. What is the percent increase? Write a complete answer — Mei will compare with a partner.
Answer. 10%
Change = 5; divide by 50 → 10%.
11.
Think
Ava tried this problem:
A price goes from $80 to $72. What is the percent decrease?
Ava wrote 20%. That is not correct. What is the right answer?
Answer. 10%
Ava’s answer 20% is off. Change = 8; divide by 80 → 10%.
12.
Think
Owen tried this problem:
A price goes from $80 to $88. What is the percent increase?
Owen wrote -10%. That is not correct. What is the right answer?
Answer. 10%
Owen’s answer -10% is off. Change = 8; divide by 80 → 10%.

Original extra practice. Keys are computed from the items, not guessed.

L21 · Percent change and percent error