Integrated Algebra - Name Date

Integrated Algebra -
Name
NOTES: Percent Applications
Date
Today’s Objective
 Review how to order fractions, decimals and percents.
 Apply what we know about percents to common real-world applications.
Percent/Fraction/Decimal “Quick Review”
Write the following list of numbers in order from least to greatest:
1
1
, 5.3%, 5.1, 0.005,
20
2
Commission
A commission is money paid to a person or a company for making a sale. Usually, the
commission is a PERCENT of the total amount made.
1. A telemarketer earns $350 per week, plus 12% commission on her sales. Find her total
pay for a week in which she made $940 in sales.
Simple Interest
When you borrow money from a bank, interest is the amount of money charged for borrowing
that money. You can also earn interest when you deposit money into a bank. You earn money,
because the bank will use YOUR money when someone else needs to borrow money.
We use a nice, neat formula to compute simple interest:
Interest Rate as a DECIMAL
(r)
Simple Interest
I = prt
(I)
Time, in YEARS
(t)
Principal - $$ you
borrow or invest
(p)
1. Find the simple interest earned after 2 years
on an investment of $3000 at 4.5% interest
earned annually.
2. The simple interest paid on a loan
after 6 months was $306. The
annual interest rate was 8%. Find
the principal amount.
Tip (Gratuity) and Sales Tax
A tip is an amount of money added to a bill for a service; it is usually a percent of the bill
before sales tax is added.
1. Most restaurants automatically add in
a tip of 18% for parties of 6 or more.
Find the gratuity that would be added to
a bill of $113.82 for a group of 8 people.
2. Estimate how much a 15% tip would
be on a check for $21.98.
Sales tax is a percent of an item’s cost that is added to the bill.
1. Connecticut’s sales tax rate is 6.35%.
Find the amount of tax that would
be paid on a clothing bill of $164.53.
2. Estimate how much tax would be paid
on a pair of shoes that cost $68.50
when the sales tax rate is 8.25%.