1. Lesson 7 Finding the Percent of a Total We frequently need to find the percent of a number, such as “What percent of the students take a bus to school?”

2. Example 1 What is 27% of 1,500? Strategy: Change the percent to a decimal and multiply. Step 1: Change the percent to a decimal. 27% = 0.27. Step 2: Multiply by the decimal. 1,500 x 0.27 = 405

3. Solution 27% of 1,500 is 405.

4. Example 2 Stacy invested $2,500 in an investment account that earns 5% interest per year. After one year, how much interest did the account earn?

5. Strategy: Change the percent to a decimal and multiply. Step 1: Change the percent to a decimal. 5% = 0.05 Step 2: Multiply by the decimal. 2,500 x 0.05 = 125

6. Solution The investment account earns $125 after one year.

7. Example 3 A computer is on sale for 15% off the regular price. If the regular price is $1,200, then what is the sale price?

8. Strategy: Find the amount of discount and subtract. Step 1: Change the percent to a decimal. 15% = 0.15 Step 2: Find the amount of the discount. Multiply: 0.15 x $1,200 = $180 Step 3: Subtract the discount from the regular price. $1,200 - $180 = $1,020

9. Solution The sale price is $1,020.

10. Example 4 Forty percent of the 300 students who graduated from Dorado Elementary School went to Westside Middle School. Fifty percent of the 200 students who graduated from the Buena Vista Elementary School last June went to Westside Middle School. Which school sent more students to Westside Middle School? How many more?

11. Strategy: Find percents of the total and compare. Step 1: Find the number of students from Dorado Elementary School who went to Westside Middle School. 40% of 300 = 0.40 x 300 =120 students Step 2: Find the number of students from Buena Vista Elementary School who went to Westside Middle School. 50% of 200 = 0.50 x 200 = 100

12. Step 3: Compare the results of Steps 1 and 2. 120 students from Dorado Elementary School is greater than 100 students from Buena Vista Elementary School. Step 4: Find how many more students from Dorado Elementary School went to Westside Middle School. Subtract 120 – 100 = 20

13. Solution 20 more students from Dorado Elementary School than from Buena Vista Elementary School went to Westside Middle School.