Do Now 4/12/11 Take out HW from last night. Take out HW from last night.  Text p. 365, #8-16 evens and #15 Copy HW in your planner. Copy HW in your planner.  Text p. 365, #18, 20, 23, 26  Text p. 809, #25-36 all  Quiz sections Wednesday (Bring notecard for quiz)  Chapter 7 Test Friday In your notebook, answer the following question. Find the simple interest on an account with the following: interest rate = 7%, principal = $325, time = 8 years. What is the account balance after the 8 th year? In your notebook, answer the following question. Find the simple interest on an account with the following: interest rate = 7%, principal = $325, time = 8 years. What is the account balance after the 8 th year? Interest = (325)(0.07)(8) = $ = $ Balance = Principal + Interest = $325 + $ = $325 + $ = $507.00

Homework Text p. 365, #8-16 evens & 15 8) $500; $1750 8) $500; $ ) $72.90; $ ) $72.90; $ ) $4; $104 12) $4; $104 14) $306 14) $306 16) 6.25% 16) 6.25% 15) 15) BalancePrincipal Interest Rate Time $5,000$4,0005% 5 years $11,160$9,0008% 36 months $3,207$3,0004.6% 18 months

Objective SWBAT calculate interest earned and account balances SWBAT review percent of change, percent applications, and simple and compound 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. Section 7.7 “Simple and Compound Interest” SIMPLE INTEREST-

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 months7 months10 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. 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. Account balance– the amount of money in an account.

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 $ This makes more “cents”…

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 Time = 6

Quiz sections Review

The percent of change of a quantity is given by: The percent is a PERCENT of INCREASE if the quantity increased and it is a PERCENT of DECREASE if the quantity decreased. Amount of change Amount of change Original amount Section 7.5 “Percent of Change” Percent of change indicates how much a quantity increases or decreases with respect to the original amount.

Section 7.6 “Percent Applications” Percents can be applied to many everyday ordinary activities: everyday ordinary activities: 1) markups 2) discounts 3) sales tax 4) tips

Markups Retail price = Wholesale price + Markup (% of wholesale price) Discounts Sale price = Original price – Discount (% of original price) Sales Tax and Tips Total cost = Food bill + Sales tax (% of bill) + Tip

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. Section 7.7 “Simple and Compound Interest” SIMPLE INTEREST-

Finding an Interest Rate… 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

This makes more “cents”… COMPOUND INTEREST- Is interest that is earned on BOTH the principal and any interest that has been earned previously. 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. Account balance– the amount of money in an account.

Notecard On one side of your notecard, you may write in the formulas for percent of change, percent applications, and simple and compound interest. Simple InterestCompound InterestPercent of Change Markup Retail price = Wholesale price +Markup (% of wholesale price) Discount Sale price = Original price –Discount (% of original price) Sales Tax & Tip Total price = Original price + Sales Tax (% of original price) +Tip

Classwork Text p. 365, #18, 20, 23, 26 Text p. 365, #18, 20, 23, 26