Algebra 2.9Applications 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?

Warm-up

Homework Check

Homework Check

Review 2.8 with WS

Review 2.8 with WS

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 $67.95. 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 $27.88. Estimate a 15% tip.

Example 3:

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

Finish Stations

Lesson Quiz