# Your Math Help is on the Way!  ### More Math Help

Try the Free Math Solver or Scroll down to Tutorials!

 Depdendent Variable

 Number of equations to solve: 23456789
 Equ. #1:
 Equ. #2:

 Equ. #3:

 Equ. #4:

 Equ. #5:

 Equ. #6:

 Equ. #7:

 Equ. #8:

 Equ. #9:

 Solve for:

 Dependent Variable

 Number of inequalities to solve: 23456789
 Ineq. #1:
 Ineq. #2:

 Ineq. #3:

 Ineq. #4:

 Ineq. #5:

 Ineq. #6:

 Ineq. #7:

 Ineq. #8:

 Ineq. #9:

 Solve for:

 Please use this form if you would like to have this math solver on your website, free of charge. Name: Email: Your Website: Msg:

# Section 8.1 - Percents

• Definition: Percents represent numbers as part of 100

• Converting Fractions to Decimals to Percent:
1. Divide the fraction, it is now a decimal.
2. Move decimal point two places to the right (multiply by 100)
3. Tack a % sign onto the end

Example (Checkpoint 1): 1/8 = 0.125 = 12.5%
Example (Checkpoint 2): 0.023 = 2.3%

• Converting Percent to Decimals
1. Move the decimal point two places to the left (divide by 100)
2. Remove away the percent sign
Example (Checkpoint 3a): 67% = 0.67

•Percentages are used frequently in Application Exercises

Example (Checkpoint 4): In England, the average price per gallon of premium gas is \$4.30. Of
this amount, \$3.44 is for taxes. What percent of fuel cost is for taxes?
Solution: • Recall that “of” in math is multiplication. To find percent “of” a number, change the percent to a
decimal and multiply

Example (Checkpoint 6): Each year 8000 Americans suffer spinal cord injuries. 13% of these are
due to sports injuries. How many spinal cord injuries are due to sports injuries each year?
Solution: 13% of 8000 = 0.13 (8000) = 1040 injuries due to sports

•Definition: Sales Tax is a tax rate (as a percentage) times purchase price

Example (Checkpoint 7): What is the total price of an item for \$1260 if the sales tax is 6%?
Solution:
price + tax = 1260 + 6% of 1260 = 1260 + 0.06 (1260)
= 1260 (1 + 0.06) = 1260 (1.06) = \$1335.60

• Definition: Discounts are percentage amounts taken off of the sales price

Example (Checkpoint 8): A CD player is originally \$380, with 35% off. Find the purchase price
Solution: original price – discount = 380 – 0.35 (380) = 380 (1 – 0.35) = \$247

•Definition: Percent increase/decrease is used to compare changes
It is found with the formula: A positive result indicates an increase, and a negative result indicates a decrease.

Example (Checkpoint 9): Sales went from 1.7 billion in 1998 to 2.2 billion in 1999. What is the
percent increase?
Solution: 