Algebra 2.9 Applications of Percents

Learning Targets Language Goal  Students will be able to use common applications of percents. Math Goal  Students will be able to estimate with percents. Essential Question  Where do you use percents in the world around you?

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Review 2.8 with WS

Vocabulary Commission: money paid to a person or company for making a sale, usually a percent of the sale amount. Interest: The amount of money charged for borrowing or investing. Sales Tax: a percent of the cost of an item that is charged by governments to raise money. Principal: the amount of money borrowed or invested Tip: The amount of money added to a bill for a service.

Example 1: Business Application  A. Ms. Barns earns a base salary of $42,000 plus a 1.5% commission on sales. Her total sales one year were $700,000. Find her total pay that year.

Example 1: Business Application  B. A telemarketer earns $350 per week plus a 12% commission on sales. Find her total pay for a week in which her sales are $940.

Example 1: Business Application  C. Mr. Cortez earns a base salary of $26,000 plus a sales commission of 5%. His total sales for one year were $300,000. Find his total pay for the year.

Example 2: Finance Application  Simple Interest Paid Annually  Formula: I = Prt  I=Simple Interest  P=Pricipal,  r=Interest rate per year as a decimal  t=time in years

Example 2: Finance Application  Find the simple interest paid annually for 2 years on a $900 loan at 16% per year.

Example 2: Finance Application  After 3 months the simple interest earned annually on an investment of $7000 was $63. Find the interest rate.

Example 2: Finance Application  Find the simple interest earned after 2 years on an investment of $3000 at 4.5% interest earned annually.

Example 2: Finance Application  The simple interest paid on a loan after 6 months was $306. The annual interest rate was 8%. Find the principal.

Example 2: Finance Application  Find the simple interest paid for 3 years on a $2500 loan at 11.5% per year.

Example 2: Finance Application  After 6 months, the simple interest earned on an investment of $5000 was $45. Find the interest rate.

Example 3:  The dinner check for Maria’s family is $ Estimate a 15% tip.

Example 3:  The sales tax rate is 6.25%. Estimate the sales tax on a shirt that costs $29.50.

Example 3:  Estimate a 15% tip on a check for $29.98

Example 3:  Estimate the tax on shows that cost $68.50 when the sales tax rate is 8.25%

Example 3:  Lunch at a restaurant is $ Estimate a 15% tip.

Example 3:  The sales tax rate is 7.25%. Estimate the sales tax on a book that costs $19.97.

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