Algebra 1

Section 3 - 7

Objectives

• I can find percent of increase or decrease in story problems

Vocabulary

• Percent of Increase – New number is greater than the original

Vocabulary

• Percent of Decrease – New number is less than the original

State whether the following is a percent of increase or a percent of decrease. Then find the percent of change.

Original 32New 40

State whether the following is a percent of increase or a percent of decrease. Then find the percent of change.

Original 32New 40

State whether the following is a percent of increase or a percent of decrease. Then find the percent of change.

Original 32New 40

State whether the following is a percent of increase or a percent of decrease. Then find the percent of change.

Original 32New 40

32x = 800

State whether the following is a percent of increase or a percent of decrease. Then find the percent of change.

Original 32New 40

32x = 800

32 32

x = 25

State whether the following is a percent of increase or a percent of decrease. Then find the percent of change.

Original 32New 40

32x = 800

32 32

x = 25% Increase

State whether the following is a percent of increase or a percent of decrease. Then find the percent of change.

Original 20New 4

State whether the following is a percent of increase or a percent of decrease. Then find the percent of change.

Original 20New 4

State whether the following is a percent of increase or a percent of decrease. Then find the percent of change.

Original 20New 4

State whether the following is a percent of increase or a percent of decrease. Then find the percent of change.

Original 20New 4

20x = 1,600

State whether the following is a percent of increase or a percent of decrease. Then find the percent of change.

Original 20New 4

20x = 1,600

20 20

State whether the following is a percent of increase or a percent of decrease. Then find the percent of change.

Original 20New 4

20x = 1,600

20 20

x = 80

State whether the following is a percent of increase or a percent of decrease. Then find the percent of change.

Original 20New 4

20x = 1,600

20 20

x = 80% Decrease

The National Football League (NFL) has a standard field of 120 yards. The Canadian Football League has a standard field that is 25% longer. What is the length of a CFL field?

The National Football League (NFL) has a standard field of 120 yards. The Canadian Football League has a standard field that is 25% longer. What is the length of a CFL field?

The National Football League (NFL) has a standard field of 120 yards. The Canadian Football League has a standard field that is 25% longer. What is the length of a CFL field?

The National Football League (NFL) has a standard field of 120 yards. The Canadian Football League has a standard field that is 25% longer. What is the length of a CFL field?

100x = 3,000

The National Football League (NFL) has a standard field of 120 yards. The Canadian Football League has a standard field that is 25% longer. What is the length of a CFL field?

100x = 3,000100 100

x = 30

The National Football League (NFL) has a standard field of 120 yards. The Canadian Football League has a standard field that is 25% longer. What is the length of a CFL field?

100x = 3,000100 100

x = 30 150 yards

A used book store will buy a book for $5. The store then sells the book for 25% more. What does a $5 book sell for?

A used book store will buy a book for $5. The store then sells the book for 25% more. What does a $5 book sell for?

A used book store will buy a book for $5. The store then sells the book for 25% more. What does a $5 book sell for?

A used book store will buy a book for $5. The store then sells the book for 25% more. What does a $5 book sell for?

100x = 125

A used book store will buy a book for $5. The store then sells the book for 25% more. What does a $5 book sell for?

100x = 125100 100

x = $1.25 more

A used book store will buy a book for $5. The store then sells the book for 25% more. What does a $5 book sell for?

100x = 125100 100

x = $1.25 more $6.25 Selling Price

The percent of increase is 25%. If the new number is 10, find the original.

The percent of increase is 25%. If the new number is 10, find the original.

The percent of increase is 25%. If the new number is 10, find the original.

The percent of increase is 25%. If the new number is 10, find the original.

25x = 100(10 – x)

25x = 1,000 – 100x+100x +100x125x = 1,000

The percent of increase is 25%. If the new number is 10, find the original.

25x = 100(10 – x)

25x = 1,000 – 100x+100x +100x125x = 1,000125 125

The percent of increase is 25%. If the new number is 10, find the original.

25x = 100(10 – x)

25x = 1,000 – 100x+100x +100x125x = 1,000 x = 8125 125

The percent of increase is 25%. If the new number is 10, find the original.

25x = 100(10 – x)

25x = 1,000 – 100x+100x +100x125x = 1,000 x = 8 original number125 125

Stop the guided notes here. We will finish the rest of the slideshow in class.

A meal for 2 at a restaurant costs $32.75. If the sales tax is 5%, what is the cost of the meal?

A meal for 2 at a restaurant costs $32.75. If the sales tax is 5%, what is the cost of the meal?

A meal for 2 at a restaurant costs $32.75. If the sales tax is 5%, what is the cost of the meal?

A meal for 2 at a restaurant costs $32.75. If the sales tax is 5%, what is the cost of the meal?

100x = 163.75

A meal for 2 at a restaurant costs $32.75. If the sales tax is 5%, what is the cost of the meal?

100x = 163.75100 100

x = 1.6375 in tax

$32.75 + $1.6375 = $34.39

A dog toy is on sale for 20% off the original price of $3.80. What is the discounted price?

A dog toy is on sale for 20% off the original price of $3.80. What is the discounted price?

A dog toy is on sale for 20% off the original price of $3.80. What is the discounted price?

A dog toy is on sale for 20% off the original price of $3.80. What is the discounted price?

100x = 76

A dog toy is on sale for 20% off the original price of $3.80. What is the discounted price?

100x = 76100 100

x = $0.76 less

$3.80 - $0.76 = $3.04

ClassworkPg 162

14 – 44 (even)