7.rp.3b day 4 first day objective: i can find simple interest

7.RP.3bDay 4 first day

• Objective: I can find simple interest.

Journal

• Sarah estimated she would need 5 pillows but she actually used 8. What is her percent error?

Review

• Ted guessed he would spend $63 at the store but actually spent $89. What was his percent error?

Quiz

Angelina estimated she would buy $56 worth of groceries but she actually spent $45. What was her percent error?

Grade Homework - Evens

Pg 162 - #2: $98.5Pg 163 - #2: $1,080.00

#6: Sport CityPg 164 - #10: In ClassPg 165 - #16: $26.80

#18: $4.90

Notes

• When you put money in the bank you earn interest.

• Interest is money you are paid when you invest or money you pay when you borrow from someone else.

Notes

• Principal is the amount you borrowed or invested.

• We use the letter “P” for principal.

• John borrowed $2000 to buy a car.

Notes

• The interest rate is the percent that you pay because you borrowed the money.

• John paid a 3% interest rate on his car.

• We use “r” for rate.

Notes

• Time is how long you borrowed or invested your money. Time is in years.

John is going to make payments on his car for 4 years.

We use “t” for time.

Notes

• John borrowed $2000 at a 3% interest rate for 4 years.

Notes

• Interest = principal * rate * time

• I = prt

Notes

• John borrowed $2000 at a 3% interest rate for 4 years.

• I = prt

Notes

• Mrs. Ramirez is investing $400 in a savings account at a simple interest rate of 2%. She plans on investing the money for 6 months. How much interest will she make?

Notes

• Arnold puts $580 into a savings account. The account pays 3% interest. How much will he earn in 5 years?

Notes

• Jenny puts $1,560 in a savings account. The account will pay 2.5% simple interest. How much interest will she earn in 3 years?

Notes

• Mrs. Hanover borrowed $1,400 at a rate of 5.5% per year. How much simple interest will she pay if it takes 8 months to repay the loan?

Notes

• Howard charged $425 to his credit card. If it has an interest rate of 9.9%, how much will he pay after one month?

Homework

• Lesson 8 Skills Practice