2.7 Percent of Change

Sale Price and Discount

Dave Wesley and Ed Judd

Percent of Increase or Decrease

• Amount of Change Original Amount

If Mr. Wesley has 20 students this period and 25 students next period, what is the percent of change?

Percent of Increase or Decrease• Amount of Change Original Amount

If Mr. Wesley has 20 students this period and 25 students next period, what is the percent of change?

• 25 – 20 Amount Change 20 Original Amount

Percent of Increase or Decrease• Amount of Change Original Amount

If Mr. Wesley has 20 students this period and 25 students next period, what is the percent of change?

25 – 20 20

5/20 = .25 = 25%

increase

Percent of Increase or Decrease

• Amount of Change Original Amount

• If Mr. Judd has 20 students this period and 5 students next period, what is the percent of change?

Percent of Increase or Decrease

• Amount of Change Original Amount

• If Mr. Judd has 20 students this period and 5 students next period, what is the percent of change?

• 20 – 5 Amount Change 20 Original Amount

Percent of Increase or Decrease• Amount of Change Original Amount

• If Mr. Judd has 20 students this period and 5 students next period, what is the percent of change?

• 20 – 5 Amount Change 20 Original Amount

• 15/20 = .75 = 75%

decrease

Percent of Change

• If a wrestler weighs 110 pounds, what is his percent of increase to move up to the 112 pound weight class or what is his percent of decrease to move down to the 103 pound weight class?

Percent of Increase• If a wrestler weighs 110 pounds,

what is his percent of increase to move up to the 112 pound weight class or his percent of decrease to move down to the 103 pound weight class?

To move up, he must gain 2 pounds.

112-110 = 2 = 0.018110 110

(rounded to the nearest thousandth)

Percent of Increase• If a wrestler weighs 110 pounds,

what is his percent of increase to move up to the 112-116 pound weight class or his percent of decrease to move down to the 103-107 pound weight class?

To move up, he must gain 2 pounds.

2/110 = .018 = 1.8 % increase

(rounded to the nearest tenth of a percent.)

Percent of Decrease• If a wrestler weighs 110 pounds,

what is his percent of increase to move up to the 112 pound weight class or his percent of decrease to move down to the 103 pound weight class?

To move down, he must lose 3 pounds.

110-103 = 7 = 0.064110 110

(rounded to the nearest thousandth)

Percent of Decrease• If a wrestler weighs 110 pounds,

what is his percent of increase to move up to the 112 pound weight class or his percent of decrease to move down to the 103 pound weight class?

To move down, he must lose 7 pounds.

7/110 = .064 = 6.4 % decrease

(rounded to the nearest tenth of a percent.)

PercentIncrease or Decrease

Percent of Decrease

New car $17,000

Value now $13,500

PercentIncrease or Decrease

Percent of Decrease

New car $17,000

Value now $13,500

Amount change: 3,500Original Amount: 17,000

0.206 = 20.6% (nearest tenth %)

PercentIncrease or Decrease

Percent of Increase

Baseball card $3

Value now $9

PercentIncrease or Decrease

Percent of Increase

Baseball card $3

Value now $9

Amount change: 6Original Amount: 3

2.00 What is this as a percent?

Sale Price and Discount

State Sales Tax

ALABAMA 4

ALASKA none

ARIZONA 5.6

ARKANSAS 6

CALIFORNIA 8.25

COLORADO 2.9

CONNECTICUT 6

DELAWARE none

FLORIDA 6

GEORGIA 4

HAWAII 4

IDAHO 6

ILLINOIS 6.25

INDIANA 6

IOWA 5

KANSAS 5.3

KENTUCKY 6

LOUISIANA 4

MAINE 5

MARYLAND (5) 6

MASSACHUSETTS 5

MICHIGAN 6

MINNESOTA 6.5

MISSISSIPPI 7

MISSOURI 4.225

MONTANA none

NEBRASKA 5.5

NEVADA 6.5

NEW HAMPSHIRE none

NEW JERSEY 7

NEW MEXICO 5

NEW YORK 4

NORTH CAROLINA

(6) 4.25

NORTH DAKOTA 5

OHIO 5.5

OKLAHOMA 4.5

OREGON none

PENNSYLVANIA 6

RHODE ISLAND 7

SOUTH CAROLINA 6

SOUTH DAKOTA 4

TENNESSEE 7

TEXAS 6.25

UTAH 4.65

VERMONT 6

VIRGINIA 5 (2)

WASHINGTON 6.5

WEST VIRGINIA 6

WISCONSIN 5

WYOMING 4

DIST. OF COLUMBIA 5.75

How to find the sales tax!

• First find out what tax rate you will be paying.• In California the tax rate is 8.25%! • Convert your percentage to a decimal by moving your decimal

two spaces to the left.

Ex. 8.25% = .0825 (Don’t forget to add a zero)

• Multiply the decimal form of the tax rate by the price of the item you are purchasing.Ex. .0825 x $ cost of the item

How to find the sales tax!

• So if an item costs $5.00• Sales tax is 8.25%• Convert 8.25% to .0825• So .0825 x $5 = $.41• The sales tax is $.41• But the total price of the item is

$5.00 + $.41 = $5.41

How to find the Discount & Discounted Price

1. Find out the % of the discount. Convert the % to a decimal.

2. Multiply the decimal by the original price.3. Take the answer in step 2 and subtract it from the

original price.Example

1) Discount 20% = .20, 2) $10 x .20 = $2.003) $10.00 - $2.00 = $8.00

Hollister Shirt $10The tax is 8.25%

• 1. How much would you spend on taxes for this shirt?

• $.83• 2. What would be the

total cost of this shirt?• $10.83

$45.00 iPod shuffle 1GBtax rate = 8.25%

3. What will the sales tax be if you purchase this item?

$3.71

4. What will the total price be if you purchase this item?

$48.71

E-matic 4GB Video MP3 Player with 2.4" Screen, Camera and Video Recorder $49.00

• 5. What will be the total of the state sales tax?

• $4.04

• 6. What will be the total price of the MP3 Player after the state tax of 8.25% is applied?

• $53.04

Tax rate 8.25%

Xbox 360 for $199.99• The Discount is 25%• 9. What is the discount?• $ 50.00• 10. What is the price after

the discount?• $149.99• 11. What is the price after

the discount and after taxes?

• $162.36

Ipod Touch for $229.99

• The tax rate is 4%

• 12. What is the tax?• $ 9.20

• 13. What is the total price after taxes?

• $239.19

Discount and Sale Price

• Lets say you are going to purchase a $95 graphing calculator. You are able to get a 20% discount and must pay 7.5% sale tax.

Stop doing this the long way! An algebraic shortcut to find your total cost is muchEasier and saves time!

Are you ready………….

Discount and Sale Price

Calculator $95 x (.80) = $76

Total Price with Tax

Calculator $76 x (1.075) = $81.70

+

Total Price with Tax

Calculator x Cost Percentage x Total Tax $95 x (.80) x (1.075) =

$81.70

Final cost with discountAnd tax included!

Easy Game………………..