1. Do now
Warm-up: Add these words to your vocabulary section of your notebook
18. Percent change: The ratio of the amount of change to the original amount represented as a percent
19. Percent increase: The % change found when the original amount increases
20. Percent decrease: The % change found when the original amount decreases

2. Homework questions? Answers: 1. 30% 2. 120% 3. 28 4. 48 5. $180 6. 100
1. 30% %
3. 28
4. 48
5. $180
7. $75
8. Ex. 12 is what percent of 10?

3. 2-9 Review
What is the total cost of a $48.40 meal at a restaurant after including a 15% tip?

4. Quiz Review
A rare disease has been discovered that affects 16 out of every 10,000 students who don’t do their homework. What percent of students who don’t do their homework are affected?

5. Quiz review
What percent of 15 is 75?

6. Quiz Review
What is 63% of 150?

7. Quiz review
160% of what number is 200?

8. Quiz review
You deposit $150 in a savings account that earns simple interest at a rate of 5.5% per year. How much interest will you have earned after 4 years?

9. Quiz
Time!

10. 2-10 Change expressed as a percent

11. Table of contents 1 Page # topic date
? Solving One-Step Equations 2/11/15
? 2-2 Solving Two-Step Equations 2/12/15
? 2-3 Solving Multi-Step Equations 2/17/15
? Solving Equations with 2/18/15
Variables on Both Sides
? 2-5 Literal Equations and Formulas 2/19/15
? Ratios, Rates & Conversions
? Solving Proportions
? 2-8 Proportions & Similar Figures
? 2-9 Percents
? Change Expressed as a Percent 1

13. In the first example,
did the sweater have
a percent increase or
decrease?
Percent change
Percent change expresses an amount of change as a percent of the original.
Percent increase is when the new amount is greater than the original amount
Percent decrease is the new amount is less than the original amount

14. Percent change formulas

15. Finding a percent decrease
A coat is on sale. The original price of the coat is $82. The sale price is $ What is the discount expressed as a percent change?

16. You try – find the percent decrease
The average monthly precipitation for Chicago, Illinois, peaks in June at 4.1 inches. The average monthly precipitation in December is 2.8 inches. What is the percent decrease from June to December?

17. Finding a percent increase
A store buys an electric guitar for $295. The store then marks up the price of the guitar to $340. What is the markup expressed as a percent change?

18. You try – find the percent increase
In one year, the toll for passenger cars to use a tunnel rose from $3 to $ What was the percent increase?

20. Finding percent error
A decorator estimates that a rectangular rug is 5 ft by 8 ft. The rug is actually 4 ft by 8 ft. What is the percent error in the estimated error?

21. You try – find the percent error
You think that the distance between your house and a friend’s house is 5.5 miles. The actual distance is miles. What is the percent error in your estimation?