Do Now 2/20/14 Take out your HW from last night. 6.6 Puzzle Time Practice Copy HW in your planner. Text p. 248, #7-16 all, 19, 20 In your notebook, put the following heading on the top of a new page. Section 6.4 “Percent of Change”

Homework Puzzle Time 6.6 1) $59.40 2) $57.60 3) $53.10 4) $97.50 5) $68.25 6) $58 7) $24.50 8) $42 9) $44 10) $36 11) $3.12 12) $2842 13) $11.99 14) $1261.20 15) $735 “What Does A Monster Say When Introduced?” PLEASED TO EAT YOU

Objective SWBAT solve problems involving percent of change

Section 6.4 “Percent of Change” the amount that a number increases or decreases written as a percent amount of change original amount Percent of change = x 100 If the amount goes up, it is a PERCENT of INCREASE. If the amount goes down, it is a PERCENT of DECREASE.

Amount of change Original amount x 100 Before: 30 After: 45 Find the percent of increase or decrease (round to the nearest tenth of a %). Before: 30 After: 45 50% increase Before: 115 After: 46 60% decrease Before: 116 After: 146 25.9% increase

≈0.181818 actual change original amount 200 1100 = ≈18.2% increase The enrollment of Howell Middle School South in 2010-2011 was 1100 students. In the year 2011-2012 the enrollment was 1300 students. What is the percent of increase or decrease between the two years? From 2010-2011 to 2011-2012 the enrollment increased by 200, therefore our answer is a percent of increase. 2011-2012: 1300 2010-2011: – 1100 change: 200. ≈0.181818 actual change original amount 200 1100 Percent of increase = = ≈18.2% increase

amount of change original amount 0.2 million 2 million =0.1 =10% There were 2.2 million computers used in public schools in 1991 and 2 million in 1990. Find the percent of increase. From 1990 to 1991 the number of computers used increased by 0.2 million or 200,000. 1991: 2.2 million 1990: - 2.0 million change: 0.2 million or 200,000. amount of change original amount 0.2 million 2 million =0.1 Percent of increase = =10% increase

Scenario 3: amount of change original amount $9.20 $307.99 =0.0298711 If a customer brings an ad that shows a competitor is selling an item for less, you are permitted to match the competitor's price as long as the percent of discount is 15% or less. a). The newest Blu-ray disc player is listed at $307.99. You notice on your way to work that the same player is for sale at another store for $298.79. Would you be allowed to match this store's price if asked? Explain. amount of change original amount $9.20 $307.99 =0.0298711 Percent of decrease = ≈3% decrease Yes, you would be permitted to match the price of $298.79.

Scenario 3: =$59.97 x 5% shipping = $62.97 amount of change If a customer brings an ad that shows a competitor is selling an item for less, you are permitted to match the competitor's price as long as the percent of discount is 15% or less. b). The store sells a wireless Internet router for $74.75. A customer has printed out a page from the Internet that shows the same router for $59.97 plus 5% shipping and handling. Can you match this price? Explain. =$59.97 x 5% shipping = $62.97 amount of change original amount $11.78 $74.75 =0.15759… Percent of decrease = ≈16% decrease No, you would not be permitted to match the price on the Internet because the discount is greater than 15%.

Percent Applications There were about 198,000 spectators at the NCAA Final Four in 1995. The number of spectators increased by about 12% from 1995 to 2002. About how many spectators were there in 2002? Spectators in 2002 = Spectators in 1995 + Amount of increase = 198,000 + = 198,000 + 23,760 = 221,760

Percent Applications In 1983, the average price of CD was $21.50. By 2000, the average price had decreased by 34.8%. What was the average price of a CD in 2000? Price in 2000 = Price in 1983 - Amount of Decrease = $21.50 - = $21.50 - 7.48 = $14.02

24 Homework Text p. 248, #7-16 all, 19, 20