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Percent of Change. Lesson 4.4 Objectives: To solve problems involving percent of increase or decrease. Real World Application.
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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