Warm Up 1.14 is 2% of what number? is 13% of what number? 3. 30% of what number is 12? % of what number is 189?

Percent of Increase or Decrease Section 6.5

Objective Calculate the percent of increase or decrease of a quantity. (NS 1.6) Solve problems that involve discount and markups. (NS 1.7)

Words to Know Percent of change - tells how much a quantity has increased or decreased relative to the original amount. amount of change original amount percent of change =

Words to Know Percent of increase describes how much the original amount increases. Percent of decrease describes how much the original amount decreases.

Finding Percentage of Change Percent of Change = New Amount – Original Amount Original Amount

Finding Percent of Change Percent of Change = 2000 Enrollment – 1999 Enrollment 1999 Enrollment The enrollment at a middle school for 1999 was 400 students and for 2000 it was 420 students. Find the percent of change from 1999 to 2000? Percent of Change = 420 – = 5%

Finding Percent of Increase Percent of Increase = Enlarged Width – Original Width Original Width You place a 5 inch by 7 inch photograph in a photo enlarger. You want to enlarge the photograph so it measures 7 in. by 9.8 in. to fit into a frame. What enlargement setting should you use? Percent of Change = 7 in. – 5 in. 5 in. 2 in 5 in 0.4= 40% = 40% + 100%= 140%

Finding Percent of Decrease Percent of Increase = New members – Original Members Original Members The number of nearly memberships sold at a recreational center in 1996 was 422. In 1997, 394 yearly memberships were sold. Find the percent of decrease. Percent of Change = 394 – = 6.6%

Now You Try… Now You Try… Find the percent of change 1.Before 10: After 12 1.Before 128: After % +50% -75%

…One More You are enlarging a sketch that measures 4 inches by 8 inches. You want the photocopy to measure 5 inches by 10 inches. What enlargement setting should you use on the photocopier? +125%

And another… Before: 12 After: 15 Before: 150 After: 175 Before: 6 After: 4 Before: $18.20 After: $16.80

Discount & Markup Wholesale prices -the price at which a store purchases items. Retail Prices -the price at which items are sold to customers. Markup -the difference between the retail and wholesale prices.

Mark Up A store buys a shirt at a wholesale price of $13.50 and sells the shirt for $ What is the amount of markup? Markup = Retail price – Wholesale price = – = $11.45

Mark Up A store buys a stereo at wholesale price for $145. They sell the item with a 170% markup. How much is the retail price? Markup = Percent of markup Wholesale price = 170% 145 = = Now add the wholesale price and the markup = $391.50

Let’s try again Find the amount of markup or discount. Then find the final cost of the item.Find the amount of markup or discount. Then find the final cost of the item. 1. $520 surfboard; 20% discount 2. $20 concert; 125% markup 3. $95 jacket; 30% off 4. $345 TV; 80% markup.

Lesson Quiz Find each percent increase or decrease to the nearest percent. 1. from 12 to from 1625 to from 37 to from 1.25 to A computer game originally sold for $40 but is now on sale for 30% off. What is the sale price of the computer game? 14% decrease 25% increase 238% increase 32% decrease $28