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Example 4-2c Objective Find the percent of increase or decrease

Example 4-2c Vocabulary Percent of change A ratio that compares the change in a quantity to the original amount Percent of change = Final - Original Original

Example 4-2c Vocabulary Percent of increase A percent of change when the original quantity increased Will have a positive change

Example 4-2c Vocabulary Percent of decrease A percent of change when the original quantity decreased Will have a negative change

Lesson 4 Contents Example 1Find Percent of Increase Example 2Find the Percent of Decrease

Example 4-1a SHOPPING Last year a sweater sold for $56. This year the same sweater sells for $60. Find the percent of change in the cost of the sweater. 1/2 Write percent of change formula % of change = Final - Original Original “this year” refers to final Replace “final” with 60 % of change = 60 “last year” refers to original Replace “original” with This year Last year

Example 4-1a SHOPPING Last year a sweater sold for $56. This year the same sweater sells for $60. Find the percent of change in the cost of the sweater. 1/2 Subtract the numerator % of change = Final - Original Original % of change = % of change = 4. Bring down denominator 56 Divide numerator by denominator % of change = Need a percent, so multiply by 100 and add the % sign % of change = 7.14% Answer: The % is positive so it is an increase

Example 4-1c MOVIES Last year a DVD sold for $20. This year the same DVD sells for $24. Find the percent of change in the cost of the DVD. Answer: percent of increase = 20% 1/2

Example 4-2a ATTENDANCE On the first day of school this year, 435 students reported to Howard Middle School. Last year on the first day, 460 students attended. Find the percent of change for the first day attendance. 2/2 Write percent of change formula % of change = Final - Original Original “this year” refers to final this year Replace “final” with 435 % of change = 435 “last year” refers to original Last year Replace “original” with

Example 4-2a ATTENDANCE On the first day of school this year, 435 students reported to Howard Middle School. Last year on the first day, 460 students attended. Find the percent of change for the first day attendance. 2/2 % of change = Final - Original Original % of change = Subtract the numerator % of change = -25. Bring down denominator 460 Divide numerator by denominator % of change = Need a percent, so multiply by 100 and add the % sign % of change = % The % is negative so it is a decrease Answer:

Example 4-2c ANIMALS At the beginning of the summer season, the local zoo reported having 385 animals in its care. At the beginning of last year’s summer season, the zoo had reported 400 animals. Find the percent of change in the number of animals at the zoo. Round to the nearest whole percent if necessary. Answer: percent of decrease = % * 2/2

End of Lesson 4 Assignment Lesson 8:4Percent of Change All