3-8 percent of change

1. 3-8 percent of change Miss battaglia – algebra 1 CP Objective: Find percent of change and solve problems involving percent of change.

2. Warm up • Alaska is the largest state in the United States, with an area of 570,374 . It accounts for about 15% of the country’s area. Estimate the area of the United States.

3. definitions • The percent of change is the percent an amount changes from its original amount. The amount of change is the difference between these two values. • When a value increases from its original amount, you call the percent of change the percent of increase. • When a value decreases from its original amount, you call the percent of change the percent of decrease.

4. example • The number of female physicians in the US increased from 25,400 in 1970 to 104,200 in 1990. Verify this statement: From 1970 to 1990, the number of female physicians increased about 310%.

5. example • From 1970 to 1990, the total number of physicians in the US increased from 334,000 to 615,400. • Find the amount of change • Find the percent of increase.

6. agriculture • Changes in the economy have affected the location and number of farm s in the United States. Find the percent of decrease in the number of farms from 1940 to 2000.

7. agriculture • Changes in the economy have affected the location and number of farm s in the United States. Find the percent of decrease in the number of acres of farmland from 1940 to 2000.

8. Find the percent of change • a) $12 to $9 b) $1.75 to $1.25

9. classwork • http://www.mathplayground.com/percent_shopping.html

10. Homework