Percent of ChangePercent of Change

J6

Ex. 1 Percent of Increase

percent of changepercent of change -The percent an amount increases or decreases from its original amount

Percent of Change = amount of change

original amount

Find the percent of increase from 4 to 7.5

Subtract to find the amount of increase. 7.5 – 4 = 3.5

Use the ratio.Percent of increase = amount of increase

original amount 3.5 = 0.875 = 87.5% 4 The percent of increase from 4 to 7.5 is 87.5%

Now you try!

1. From 100 to 114

2. From 2.0 to 3.2

3. From 4,000 to 8,500

14%

60%

112.5%

4. The annual production of video games in the United States has more than doubled since the 1960s. Find the percent of increase from 1960 to 1990.

Year Number of Video Games

Produced

1960 88,000

1990 205,000

Percent of increase from 1960-1990 was about 133%.

Ex. 2 Finding Percent of Decrease

Find the percent of decrease from 1,500 to 1,416.

amount of decrease = 1500 – 1416 = 84

Percent of decrease = Amount of Decrease

Original Amount

84

1500

= 0.056 = 5.6%

The percent of decrease is 5.6%.

Now you try!Find each percent of decrease. Round to nearest tenth.

5. From 9.6 to 4.8

6. From 202 to 192

7. From 854.5 to 60.6

50%

5%

92.9%

Word Problem

8. A computer that costs $875 last year costs $745 this year. Find the percent of decrease to the nearest percent.

15%

Markup and DiscountMarkup and Discount

J7J7

Vocabulary

To make a profit, stores charge more for merchandise than they pay for it.

MARKUP - The amount of increase PERCENT OF MARKUP -The percent of

increase (Much like Percent of Increase).

Ex. 1 Finding markup A music store’s percent of markup is

67%. A CD costs the store $10.50. Find the markup.

Markup = percent of markup • store’s cost = 0.67 • 10.50 Markup = $7.04

Now you try!

1. A clothing store pays $56 for a jacket. The store’s percent of markup is 75%. Find the markup for the jacket.

Jacket is marked up $42.

Ex. 2 Selling Price

Store’s Cost + Markup = the Selling Price. If the markup for the CD is $7.04 and it

costs the store $10.50, how much do you pay?

If the jacket costs the store $56 and the markup is $42, how much do you pay?

2. A store pays $5 for a baseball cap. The percent of markup is 70%. Find the selling price of the cap.

.70 • $5 = $3.50 $3.50 + $5 = $8.50

Ex. 3 Finding Discount

There are TWO Methods

1st Method: Find the Discount, Then find the sale price.

2nd Method: Find the Sale Price Directly.

a. Method 1: Two Step Method

Discount = percent of discount • original price.

= 0.20 (20%) • $39.95

= $7.99

Sales Price = Original Price – Discount

= $39.95 - $7.99

= $31.96 is the price you pay after discount.

b.Method 2: One Step Method

Find the sale price directly.

The sales price equals 100% of the original price, minus 20% of the original price.

Sale Price = (100% - 20%) • Original Price

= .80 (or 80%) • Original Price

= .80 • $39.95

Sale Price = $31.96

Now you try!

3. Pants priced at $21.99 are marked 15% off. Find the new price.