Splash Screen

Lesson Menu Five-Minute Check (over Lesson 7–5) Then/Now New Vocabulary Key Concept: Percent of Change Example 1: Find the Percent of Change Example 2: Real-World Example: Find the Percent of Change Example 3: Find the Selling Price Example 4: Real-World Example: Find the Sale Price

Over Lesson 7–5 5-Minute Check 1 A.40% B.35% C.33.3% D.30% 24 is what percent of 80?

Over Lesson 7–5 5-Minute Check 2 A.75 B.74 C.73 D is 52% of what number?

Over Lesson 7–5 5-Minute Check 3 A.37.5 B C D Find 26.3% of 135.

Over Lesson 7–5 5-Minute Check 4 A.630 B.621 C.593 D.585 The girls club sold 15% more cookies this year than last year. The club sold 540 boxes of cookies last year. How many did they sell this year?

Over Lesson 7–5 5-Minute Check 5 A.18 B.17 C.16 D.15 One season the Miami Dolphins had 10 wins. This was 62.5% of the games the team played. How many games did they play?

Over Lesson 7–5 5-Minute Check 6 A.9.4% B.1.06% C.5.7% D.6% Taneesha bought a laptop for $ including tax. The laptop had a price of $ What percent sales tax did she pay?

Then/Now You have already solved real-world problems using the percent equations. (Lesson 7–5) Find percent of increase and decrease. Solve real-world problems involving markup and discount.

Vocabulary percent of change - Is the ratio that compares the change in quantity to the original amount. percent of increase – Positive increase. percent of decrease – Negative decrease. markup – The amount of increase. selling price – The amount a customer pays for an item. discount – The amount by which the selling or regular price is reduced.

Concept

Example 1 Find the Percent of Change Find the percent of change from 20 students to 24 students. State whether the percent of change is an increase or decrease. Step 1Subtract to find the amount of change. 24 – 20 = 4final amount – original amount Step 2Write a ratio that compares the amount of change to the original amount. Express the ratio as a percent.

Example 1 Find the Percent of Change Simplify. Answer: 20%; increase Step 3The decimal 0.20 is written as 20%. The percent of change is positive, so it is a percent of increase.

Example 1 A.–20%; decrease B.–25%; decrease C.20%; increase D.25%; increase What is the percent of change from 24 to 30 students?

Example 2 Find the Percent of Change Pedro had 325 trading cards. He now has 270 trading cards. Find the percent of change. Round to the nearest tenth, if necessary. Then state whether the percent of change is an increase or decrease. Step 1Subtract to find the amount of change. 270 – 325 = –55final amount – original amount Step 2Write a ratio that compares the amount of change to the original amount. Express the ratio as a percent.

Example 2 Find the Percent of Change Divide. Use a calculator. Answer: To the nearest percent, the percent of change is –16.9%. Because the percent is negative, it is a percent of decrease. Substitution

Example 2 A.–17.9%; decrease B.–21.7%; decrease C.17.9%; increase D.21.7%; increase John had $420 in his checking account at the beginning of May. At the beginning of June he had $345. What was the percent of increase or decrease to the nearest tenth?

Example 3 Find the Selling Price Find the selling price if a store pays $68 for a portable DVD player, and the markup is 35%. Method 1Find the amount of markup first. The whole is $68. The percent is 35. You need to find the amount of the markup, or the part. Let m represent the amount of the markup. Then add the markup to the cost. So, $68 + $23.80 = $ m=0.35 ● 68part = percent ● whole m=23.80Multiply.

Example 3 Find the Selling Price Method 2Find the total percent first. Use the percent equation to find 100% + 35% or 135% of the price. Let p represent the price. p=1.35 ● 68part = percent ● whole p=91.80Multiply. Answer: Using either method, the selling price is $91.80

Example 3 A.$28.80 B.$48.40 C.$67.20 D.$88.00 The markup on a pair of shoes is 40%. If the store paid $48 for a pair of shoes, what is the selling price?

Example 4 Find the Sale Price BASEBALL MITT CR Sporting Goods is having a sale. A baseball mitt has an original price of $89. It is on sale for 25% off the original price. Find the sale price of the baseball mitt. Method 1Find the amount of the discount. The whole is $89. The percent is 25. You need to find the amount of the discount, or the part. Let d represent the amount of the discount. Subtract the discount from the cost. So, $89 – $22.25 = $ d=0.25 ● 89part = percent ● whole d=22.25Multiply.

Example 4 Find the Sale Price Method 2Find the total percent first. Use the percent equation to find 100% – 25% or 75% of the price. Let p represent the sale price. p=0.75 ● 89part = percent ● whole p=66.75Multiply. Answer: Using either method, the sale price is $66.75.

Example 4 A.$11.20 B.$20.80 C.$27.00 D.$43.20 A store is having a 35% off sale. What is the sale price of a shirt normally costing $32?

End of the Lesson