Algebra 1 3 9 Percents PERCENT A percent

Algebra 1 3. 9 Percents

PERCENT A percent is a ratio that compares a number to 100. You can write percent as a fraction, as a decimal, or as a number followed by a percent symbol %.

Common Percent Equation Number Being = Compared to Base a = Percent x Base Number (p/100) x b

BASE NUMBER The base number is the number that is being compared to in any percent equation.

Three Types of Percent Problems Question Given Need to Find What is p percent of b? b and p Number compared to base, a A is p percent of what? a and p Base number, b A is what percent of b? a and b Percent, p

Number Compared to Base is Unkown 1. What is 30% of 70 feet? 2. What is 15% of 100 meters? 3. What is 20% of 90 gallons?

Base Number is Unkown 1. Fourteen dollars is 25% of what amount of money? 2. 12 is 60% of what number? 3. Twenty-eight dollars is 35% of what amount of money?

Percent is Unkown 1. 8 is what percent of 20? 2. 20 is what percent of 8? 3. One hundred eight is what percent of 36?

DISCOUNT When an item is on sale, the difference between the regular price and the sale price is called the discount. To find the discount percent, use the regular price as the base number in the percent equation.

Example A radio has a regular price of $80. You receive a 10% discount when you purchase it. Find the amount of the discount. Then find the sale price of the radio with the 10% discount.

Example You are shopping for a new pair of shoes. The shoes you like are on sale for $42, marked down from the previous price of $60. What percent is the discount?