ExerciseExercise
30%30%
15501550
Express the ratio as a percent.Express the ratio as a percent.
25%25%
15601560
Express the ratio as a percent.Express the ratio as a percent.
ExerciseExercise
3030
What is 60% of 50?What is 60% of 50?ExerciseExercise
60% of what number is 150?60% of what number is 150?250250
ExerciseExercise
What percent of 50 is 150?What percent of 50 is 150?300%300%
ExerciseExercise
Determine next year’s sales goal, N, if the company wants to increase this year’s sales of $250,000 by 15%.
Determine next year’s sales goal, N, if the company wants to increase this year’s sales of $250,000 by 15%.
N = $287,500N = $287,500
The goal is 115% of last year’s sales.
The goal is 115% of last year’s sales.
N = 1.15(250,000)N = 1.15(250,000)
Example 1Example 1
Percent Change FormulaPercent Change Formula
percent change =percent change =amount of changeoriginal amount
amount of changeoriginal amount
x 100%x 100%
Finding the Percent Change
Finding the Percent Change
1. Subtract to find the amount of change.
2. Divide the amount of change by the original amount.
Finding the Percent Change
Finding the Percent Change
3. Convert the quotient to a percent and indicate whether it is an increase or a decrease.
What is the percent change from 75 to 100?What is the percent change from 75 to 100?
100 – 75 = 25100 – 75 = 25changeoriginalchangeoriginal
25752575
== = 0.3= 0.3
The percent change is a 33.3% increase.
The percent change is a 33.3% increase.
Example 2Example 2
Find the percent change. Round to the nearest whole percent.
Find the percent change. Round to the nearest whole percent.
29%29%
original amount: 42new amount: 54
original amount: 42new amount: 54
ExampleExample
Find the percent change. Round to the nearest whole percent.
Find the percent change. Round to the nearest whole percent.
49%49%
original amount: 150new amount: 224
original amount: 150new amount: 224
ExampleExample
Find the percent change. Round to the nearest whole percent.
Find the percent change. Round to the nearest whole percent.
17%17%
original amount: 1,080new amount: 900
original amount: 1,080new amount: 900
ExampleExample
Find the percent change, to the nearest whole percent, from 19 to 16. Indicate whether it is an increase or a decrease.
Find the percent change, to the nearest whole percent, from 19 to 16. Indicate whether it is an increase or a decrease.19 – 16 = 319 – 16 = 33
193
19≈ 0.16≈ 0.16 = 16% decrease = 16% decrease
Example 3Example 3
Find the percent change from 2,400 to 2,650. Indicate whether it is an increase or decrease. Round to the nearest whole percent.
Find the percent change from 2,400 to 2,650. Indicate whether it is an increase or decrease. Round to the nearest whole percent.
10% increase10% increase
ExampleExample
Find the percent change from 13 to 18. Indicate whether it is an increase or decrease. Round to the nearest whole percent.
Find the percent change from 13 to 18. Indicate whether it is an increase or decrease. Round to the nearest whole percent.
38% increase38% increase
ExampleExample
Find the percent change from 144 to 120. Indicate whether it is an increase or decrease. Round to the nearest whole percent.
Find the percent change from 144 to 120. Indicate whether it is an increase or decrease. Round to the nearest whole percent.
17% decrease17% decrease
ExampleExample
Last year Mrs. Rutherford’s homeroom sold 56 cartons of candy bars. This year her homeroom sold 80 cartons. What was the percent change? Give the answer to the nearest tenth of a percent.
Last year Mrs. Rutherford’s homeroom sold 56 cartons of candy bars. This year her homeroom sold 80 cartons. What was the percent change? Give the answer to the nearest tenth of a percent.
Example 4Example 4
Last year Mrs. Rutherford’s homeroom sold 56 cartons of candy bars. This year her homeroom sold 80 cartons.
Last year Mrs. Rutherford’s homeroom sold 56 cartons of candy bars. This year her homeroom sold 80 cartons.
= 42.9% increase= 42.9% increase
24562456 ≈ 0.429≈ 0.429
80 – 56 = 2480 – 56 = 24
Dillon has 65 baseball cards and Joseph has 50. Dillon has what percent more than Joseph? Joseph has what percent less than Dillon?
Dillon has 65 baseball cards and Joseph has 50. Dillon has what percent more than Joseph? Joseph has what percent less than Dillon?
65 – 50 = 1565 – 50 = 15
Example 5Example 5
Dillon has 65 baseball cards and Joseph has 50. Dillon has 65 baseball cards and Joseph has 50.
Dillon has 30% more cards than Joseph. Joseph has
23% less than Dillon.
Dillon has 30% more cards than Joseph. Joseph has
23% less than Dillon.
15501550
= 30%= 30%
3010030
100== 15
651565
≈ 0.23≈ 0.23
= 23%= 23%
Find the percent change in the following problems. Indicate whether it is an increase or a decrease. Round to the nearest whole percent.
Find the percent change in the following problems. Indicate whether it is an increase or a decrease. Round to the nearest whole percent.
ExampleExample
Caleb earned $225 per week waiting on tables at a restaurant last summer. This year he earned $305 per week.
Caleb earned $225 per week waiting on tables at a restaurant last summer. This year he earned $305 per week. 36% increase36% increase
ExampleExample
A couple bought a new car for $18,995 three years ago. They just sold it for $8,000.
A couple bought a new car for $18,995 three years ago. They just sold it for $8,000.
58% decrease58% decrease
ExampleExample
Mr. Fremont’s homeroom brought in 14,000 lb. of nonperishables last year in the food drive. This year they brought in 16,500 lb.
Mr. Fremont’s homeroom brought in 14,000 lb. of nonperishables last year in the food drive. This year they brought in 16,500 lb.
18% increase18% increase
ExampleExample
Seth bought a guitar on sale for $250. It had been reduced from $290.
Seth bought a guitar on sale for $250. It had been reduced from $290. 14% decrease14% decrease
ExampleExample