Main Idea and New Vocabulary Key Concept: Percent of Change Example 1: Find Percent of Change Example 2: Find Percent of Change Lesson Menu

Find and use the percent of increase or decrease. percent of change percent of increase percent of decrease Main Idea/Vocabulary

Key Concept

Step 1 Subtract to find the amount of change. Find Percent of Change VIDEO GAMES A football video game sold for $32 last year. This year, it sells for $38. Find the percent of change. State whether the change is an increase or a decrease. Step 1 Subtract to find the amount of change. 38 – 32 or 6 final amount – original amount Example 1

= 0.1875 Divide. Use a calculator. Find Percent of Change Step 2 percent of change = = Substitution = 0.1875 Divide. Use a calculator. Example 1

Since the percent of change is positive, it is a percent of increase. Find Percent of Change Step 3 0.1875 = 18.75%. Since the percent of change is positive, it is a percent of increase. Answer: 18.75%; increase Example 1

SOCCER Last week at a sporting goods store, 28 soccer balls were sold SOCCER Last week at a sporting goods store, 28 soccer balls were sold. This week, 21 soccer balls were sold. Find the percent of change. Round to the nearest tenth if necessary. State whether the change is an increase or a decrease. A. –25%; decrease B. 25%; increase C. 33.3%; increase D. –33.3%; decrease Example 1 CYP

Step 1 Subtract to find the amount of change. Find Percent of Change SAVINGS Last year, Janine saved $240. This year, she saved $180. Find the percent of change. State whether the change is an increase or a decrease. Step 1 Subtract to find the amount of change. 180 – 240 or –60 final amount – original amount Example 2

= – 0.25 Divide. Use a calculator. Find Percent of Change Step 2 percent of change = = Substitution = – 0.25 Divide. Use a calculator. Example 2

Express the ratio as a percent. –0.25 = –25% Find Percent of Change Step 3 Express the ratio as a percent. –0.25 = –25% Since the percent change is negative, it is a percent decrease. Answer: 25%; decrease Example 2

FUNDRAISING Last year, $1,600 was raised during the walk-a-thon FUNDRAISING Last year, $1,600 was raised during the walk-a-thon. This year, $2,200 was raised. Find the percent of change. Round to the nearest tenth if necessary. State whether the change is an increase or a decrease. A. 27.3%; increase B. –27.3%; decrease C. 37.5%; increase D. –37.5%; decrease Example 2 CYP