APPLICATIONS OF PERCENT

Chapter 6

Fractions, Decimals, & Percents

A percent is a ratio that compares a number to 100

To change a decimal to a percent, multiply by 100 or move the decimal two places to the right

To change a percent to a decimal, divide by 100 or move the decimal two places to the left

To write a percent as a fraction, put it over 100 then simplify

To order from least to greatest, they must all look the same!

Example(s)

Write each fraction as a percent.1.) 2.) 3.)

Write each decimal as a percent.4.) 5.) 6.)

Write each percent as a fraction.7.) 8.) 9.)

Percents & Proportions

is = % of 100

Finding the Part Finding the Whole Finding the Percent

What number is 20% of 25? 5 is 20% of what number ? 5 is what percent of 25?

n = 20 5 = 20 5 = p25 100 w 100 25 100

Percents & Equations

= means is“of” means to multiply

Finding the Part Finding the Whole Finding the Percent

Part = p · whole Part = p · whole Part = p · whole

What is 20% of 25? 5 is 20% of what? 5 is what percent of 25?

n = 0.20 · 25 5 = 0.20 · w 5 = p · 25

Percent of Change

The percent a quantity increases or decreases from its original amount is the percent of change

Percent of change = amount of change

original amount

Example(s):

1.) The average price of a movie ticket in the United States in 1990 was $4.22. Ten years later, the average price was $5.39 In that ten-year period, average movie ticket prices increased by $1.17. Find the percent of change.

P = amount of change P = 1.17 = 0.28 = 28%

original amount 4.22

*Movie tickets prices increased about 28% from 1990 to 2000.

Example(s):

Find the percent of increase.1.) 75 to 110 2.) 50 to 90

Find the percent of decrease.3.) 190 to 183 4.) 368 to 275

Markup and Discount

markup is the amount of increase in pricemarkup is added to the store’s cost of the

item to arrive at the selling price

Percent of change = amount of change

original amount ↓ ↓

Percent of markup = markup

STORE’S COST

Example(s):

1.) Find the percent of markup on a sweater that costs a store $25 and has a selling price of $45.

markup = selling price – store’s cost = $45 – $25 = $20Percent of markup = 20 = 0.8 = 80%

25

Example(s):

1.) Find the percent of markup.Store’s cost: $26Selling price: $39

Finding percent of Discount

The amount by which the price of an item on sale is reduced is called the discount

The regular price of an item minus the discount equals the sale price of the item

Percent of change = amount of change original amount

↓ ↓ Percent of discount = discount

regular price