Do Now 2/23/12Do Now 2/23/12

Take out HW from last night.Take out HW from last night.Exploration Activities 4 & 5Exploration Activities 4 & 5

Copy HW in your planner.Copy HW in your planner.Text p. 248, #7-20 all, 23-25 allText p. 248, #7-20 all, 23-25 all

In your notebook, put the following heading In your notebook, put the following heading on the top of a new page. Section 6.4 on the top of a new page. Section 6.4 “Percent of Change”“Percent of Change”

ObjectiveObjective SWBAT solve problems involving percent of SWBAT solve problems involving percent of

changechange

If the amount goes up, it is a If the amount goes up, it is a PERCENT of INCREASE.PERCENT of INCREASE.

amount of changeamount of change original amountoriginal amount

Section 6.4 “Percent of Change”Section 6.4 “Percent of Change”

Percent of changePercent of change

x 100x 100

the amount that a number increases or decreases written as a percent

If the amount goes down, it is a If the amount goes down, it is a PERCENT of DECREASE.PERCENT of DECREASE.

Percent of change = Percent of change =

Find the percent of increase or decrease Find the percent of increase or decrease (round to the nearest tenth of (round to the nearest tenth of

a %).a %). Before: 30 Before: 30 After: 45 After: 45 Before: 115 Before: 115 After: 46 After: 46

Before: 116 After: 146 Before: 116 After: 146

50% increase 50% increase

60% decrease 60% decrease

25.9% 25.9% increase increase

Amount of changeAmount of change Original amountOriginal amount

x 100x 100

From 2010-2011 to 2011-2012 the From 2010-2011 to 2011-2012 the enrollment increased by 200, thereforeenrollment increased by 200, thereforeour answer is a percent of increase.our answer is a percent of increase.

actual changeactual changeoriginal amountoriginal amount

200200 11001100

≈ ≈0.1818180.181818

≈ ≈18.2% increase18.2% increase

The enrollment of Howell Middle School South in The enrollment of Howell Middle School South in 2010-2011 was 1100 students. In the year 2011-2012 2010-2011 was 1100 students. In the year 2011-2012 the enrollment was 1300 students.the enrollment was 1300 students.

What is the percent of increase or decrease between What is the percent of increase or decrease between the two years? the two years?

Percent of increase =

2011-2012: 13002011-2012: 1300 2010-2011: – 2010-2011: – 11001100 change: 200. change: 200.

==

From 1990 to 1991 the number of computersFrom 1990 to 1991 the number of computersused increased by 0.2 million or 200,000. used increased by 0.2 million or 200,000.

amount of changeamount of changeoriginal amountoriginal amount

0.2 million0.2 million 2 million2 million

=0.1=0.1

=10% =10% increaseincrease

There were 2.2 million computers used There were 2.2 million computers used in public schools in 1991 and 2 million in in public schools in 1991 and 2 million in 1990. Find the percent of increase.1990. Find the percent of increase.

Percent of increase = Percent of increase =

1991:1991: 2.2 million 2.2 million 1990: 1990: - 2.0 million- 2.0 million change: 0.2 million or 200,000change: 0.2 million or 200,000. .

Shopping and Business Shopping and Business ApplicationsApplications

ManufacturerManufacturerPricePrice

SaleSale

PricePriceOriginalOriginalPricePrice

RetailRetail

PricePriceDiscountDiscount

MarkupMarkup

Using a Percent of ChangeUsing a Percent of ChangeModell’s buys Nike brand sneakers from the Nike Modell’s buys Nike brand sneakers from the Nike

manufacturer for $40. Modell’s then increases the price by manufacturer for $40. Modell’s then increases the price by 150%. What is the retail price?150%. What is the retail price?

Retail priceRetail price == Wholesale Wholesale priceprice + +

Amount of Amount of IncreaseIncrease

== 4040 + +

== 4040 + + 6060

== $100$100

What is 150% of 40?

100

150

40

aor or (150% (150% ∙ ∙ 40)40)

also known as a also known as a

““MARKUP”MARKUP”

You buy a shirt that is on sale for 15% off You buy a shirt that is on sale for 15% off the original price of $25. What is the sale price?the original price of $25. What is the sale price?

== 2525 – – or (15% or (15% · 25)· 25)

== 2525 – – 3.753.75

== $21.25$21.25

Sale priceSale price ==Original Original priceprice – – Amount of Amount of

decreasedecrease

Using a Percent of ChangeUsing a Percent of Change

also known as a also known as a

““DISCOUNT”DISCOUNT”

What is 15% of 25?

100

15

25

a

Using a Percent of ChangeUsing a Percent of ChangeWinter Wonders buys snow globes from a Winter Wonders buys snow globes from a

manufacturer for $9.20 each sells them at a 95% increase in manufacturer for $9.20 each sells them at a 95% increase in price. What is the retail price?price. What is the retail price?

Retail priceRetail price == Wholesale Wholesale priceprice + +

Amount of Amount of IncreaseIncrease

== 9.209.20 + +

== 9.209.20 + + 8.748.74

== $17.94$17.94

What is 95% of $9.20?

100

95

2.9

aor or (95% (95% ∙ $9.2∙ $9.20)0)

also known as a also known as a

““MARKUP”MARKUP”

The regular price of an MP3 player is The regular price of an MP3 player is $79.99. This week the MP3 player is on sale $79.99. This week the MP3 player is on sale 25% off. What is the sale price?25% off. What is the sale price?

== 79.9979.99 – – or (25% or (25% · 79.99)· 79.99)

== 79.9979.99 – –

== $59.99$59.99

Sale priceSale price ==Original Original priceprice – – Amount of Amount of

decreasedecrease

Using a Percent of ChangeUsing a Percent of Change

also known as a also known as a

““DISCOUNT”DISCOUNT”

What is 25% of 79.99?

100

25

99.79

a

$20.00$20.00

Using a Percent of ChangeUsing a Percent of Change

There were about 198,000 spectators at There were about 198,000 spectators at the NCAA Final Four in 1995. The number of the NCAA Final Four in 1995. The number of spectators increased by about 12% from 1995 to spectators increased by about 12% from 1995 to 2002. About how many spectators were there in 2002. About how many spectators were there in 2002? 2002?

Spectators in 2002 = Spectators in 1995 + Amount of increase

= 198,000 + (12% · 198,000)

= 198,000 + 23,760

= 221,760

Using a Percent of ChangeUsing a Percent of Change

In 1983, the average price of CD was In 1983, the average price of CD was $21.50. By 2000, the average price had $21.50. By 2000, the average price had decreased by 34.8%. What was the average decreased by 34.8%. What was the average price of a CD in 2000? price of a CD in 2000?

Price in 2000 = Price in 1983 x Percent of change

= $21.50 x (100% – 34.8%)

= $21.50 x 65.2%

= $14.018 = $14.02

HomeworkHomeworkText p. 248, #7-20 all, 23-25 allText p. 248, #7-20 all, 23-25 all

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