Percent of Change and Markup and Discount

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Percent of Changeand Markup and Discount
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Academic Opener

• Solve using proportions cross products
• 1.

2.
10
16
6
b
3. On a scale drawing 2 equals 15 miles. How far
in miles is the distance between two points that
are 32 inches apart? Round to the nearest whole
number.
Write the fraction as a decimal and as a
percent. Fraction 4. Decimal 5. Percent
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Key Term

• Percent of Change-The percent a quantity
  increases or decreases from the original amount.

Amount of increase Original Amount
Percent of change
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Example 1

• Find the percent increase from 4 to 7.5.
• Amount of increase 7.5 4 3.5

Percent of increase Amount of Increase
Original Amount
0.875 87.5
The percent of increase from 3 to 7.5 is 87.5
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Example 2

• In 1970, gasoline cost 36 cents a gallon.
  Today, in 2004, it costs 1.69 a gallon. What is
  the percent increase from 1970 to 2004? (Round to
  the nearest percent.)

Amount of increase 1.69 - .36 1.33
Percent of increase Amount of Increase
Original Amount
3.69
369 Increase!
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Find the amount of decrease

• Example 3
• A computer that cost 1,099 last year now costs
  999. Find the percent of decrease to the
  nearest percent.

Percent of decrease Amount of Decrease
Original Amount
Amount of decrease is 1,099 999 100
90
The price of this computer decreased by 9!
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Practice on a few

• Tell whether the change is an increase of a
  decrease and find the percent of change.
• A. From 30 to 39 B. From 60 to 48

Remember, Percent of change Amount of
change Original amount
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Markup

• To make a profit a store charges more for
  merchandise then they pay for it.
• The amount of increase is called markup
• The percent of increase is called the percent of
  markup

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Markup

• A music stores percent of markup is 67. A CD
  costs the store 10.15. Find the markup
• Markup percent of markup x cost

The markup is 6.80
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Discount/Sale Price

• When an item goes on sale, the amount of the
  price decrease is called the discount.
• The percent of decrease is called the percent of
  discount
• The original price minus the discount is called
  the sale price

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Discount

• A video game that is regularly 39.95 is on sale
  for 20 off. What is the sale price?
• Find the discount
• Then find the sale price.

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A video game that is regularly 39.95 is on sale
for 20 off.

• Find the discount
• Discount discount x original price
• Sale Price original price discount

The Sale Price is 31.96
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Try These

• Find the markup
• The cost of the item is 1.5
• The percent markup is 70
• Find the discount
• The regular price is 100
• The percent of discount is 27

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Try These

• Find the sale price
• The regular price is 180
• The percent of discount 40
• Find the sale price
• The regular price is 100
• The percent of discount is 27