Percent, 11.1

• Percent is parts per hundred.
• It is the ratio of parts to whole multiplied by 100.
• It is a unit less measure which is use full for making comparisons.
• If you get 33 out of 40 questions on a test right, your percentage is 33/40 * 100 or 82.5%
• To convert a decimal to a percent:
  • Multiply the decimal by 100
  • Add the % sign.
• Example: .47 becomes 47%
• To convert a fraction to a percent
  • Divide the numerator by denominator to produce a decimal
  • Convert the decimal to a percent.
• Example: 4/5 = .80 = 80%
• To convert a percent to a decimal
  • Remove the % sign
  • Divide by 100
• Example 23% = .23
• Be careful with 1/2% = .5% = .005
• For percent problems use: parts/whole * 100 = percent
• Do problems 25 page 653
• Do 28, page 654
• Percent change (new-old)/old X 100,
• Do problem 41, 42 page 654
• Percent Markup: (price-cost)/cost X 100