Do Now 4/11/11 Take out HW from last night. Copy HW in your planner. Practice worksheet 7.6 odds Copy HW in your planner. Text p. 365, #8-16 evens and #15 Quiz sections 7.5-7.7 Wednesday Chapter 7 Test Friday Be ready to copy POTW#3.

A shoe store in NJ has a sale on sneakers for 15% off A shoe store in NJ has a sale on sneakers for 15% off. If the original price is$75 what is the total cost of the sneakers with tax? Sale price = Original price Discount – = 75 – (15% · 75) = 75 – 11.25 = $63.75 Total Price = Purchase Price Sales Tax + $63.75 + (63.75 x 7%) $63.75 + 4.46 $68.21

Homework Practice worksheet 7.6 odds 13) $83.64 15) $36.15 17) $19.38 19) $27.04 21) $57.40 1) $11.25 3) $273 5) $49.40 7) $30.60 9) $29.26 11) $86.51

Objective SWBAT calculate interest earned and account balances

Section 7.7 “Simple and Compound Interest” SIMPLE INTEREST- Is the product of the principal, the annual interest rate, and the time in years. Principal – the amount borrowed, loaned, or in savings. Annual interest rate – the percent of the principal you would earn (or pay) as interest in ONE year. Time in years – when time is less than a year, write time as a fraction of the year.

Writing Time in Years… Time in years – when time is less than a year, write time as a fraction of the year. Write the months as a fraction of a year. 3 months 7 months 10 months

Simple Interest You have $1,000 in a savings account in a local bank. The annual interest rate is 3%. How much interest will the bank pay you in a month? Principal = $1000 Interest rate = 3% or 0.03 Time = one month or 1/12

Simple Interest You borrowed $18,000 for a new car. The annual interest rate is 12%. What is the interest you will have to pay in two years to borrow this money? Principal = $18,000 Interest rate = 12% or 0.12 Time = two years or 2

Account Balance When an account earns interest it is added to the money in the account. The BALANCE (A) of an account that earns simple annual interest is the sum of the principal (P) and the interest (Prt). Balance

Finding an Interest Rate Suppose you save $1400 in a savings account that earns simple annual interest. After 9 months, the balance in your account is $1421. Find the annual interest rate. Principal = $1400 Balance = $1421 Time = 9 months The interest rate is 2%

This makes more “cents”… COMPOUND INTEREST- Is interest that is earned on BOTH the principal and any interest that has been earned previously. Account balance– the amount of money in an account. Principal – the amount borrowed, loaned, or in savings. Annual interest rate – the percent of the principal you would earn (or pay) as interest in ONE year. Time in years – when time is less than a year, write time as a fraction of the year.

This makes more “cents”… You deposit $300 in the bank. This is your beginning balance. The annual interest rate is 6%. Each year the simple interest is computed and then added to your beginning balance. (this is compounded interest). If this pattern continues, how much will you have in the account at the end of 3 years? Principal = $300 Interest rate = 6% Time = 3 years After 3 years you will have $357.30

Compound Interest You deposit $1,500 in a savings account in a local bank. The annual interest rate is 2.4% compounded annually. Find the balance after 6 years? Principal = $1500 Interest rate = 2.4% or 0.024 Time = 6

24 Homework Text p. 365, #8-26 evens

Word Problem You deposit $300 in the bank. This is your beginning balance. The annual interest rate is 6%. Each year the simple interest is computed and then added to your beginning balance. If this pattern continues, how much will you have in the account at the end of 3 years? After 3 years you will have $357.30 YEAR 1 YEAR 2 YEAR 3 Principal = $300 Principal = $318 Principal = $337.08 Interest rate = 6% Interest rate = 6% Interest rate = 6% Time = one year Time = one year Time = one year