Percent of Change

							Percent of Change

        Lesson 4.4
        Objectives: To solve
        problems involving
        percent of increase or
        decrease.
Real World Application
   If you’ve ever bought a package of marshmallows, you’ve
    mostly bought air. That’s right, marshmallows are 80% air!
    The marshmallow was invented in ancient Egypt and made
    with honey and the sap of the mallow plant that grows in
    swamps, or marshes.

   Today, marshmallows are mass produced and made from
    cornstarch and gelatin. In 1955, the height of marshmallow
    making in the United States, there were 30 marshmallow
    companies. Today there are only a handful.
Real World Application (continue)

   Let’s say there are only six marshmallow companies
    today. You can write a ratio that compares the
    amount of decrease in marshmallow companies to
    the original number of companies in 1955. This ratio
    can be written as a percent.

         To find the percent of increase or decrease:
   First, subtract to find the amount of change.
   Then divide by the original number.
Real World Application (continue)

   A retailer increased the price of ball-point
    pens from $0.40 to $0.45 each. What was
    the percent of increase?
   Pages 204 – 205 Check Understanding # 1-2
   Page 207 # 1- 14, 30 – 38
   Practice Worksheet 4.4 # 1 - 27