Warm-Up. Divide by 100. Write the quotient as a decimal What action does the symbol

Transcription

1 Warm-Up Divide by 100. Write the quotient as a decimal What action does the symbol mean?

2 Warm-Up Divide by 100. Write the quotient as a decimal The symbol means to send a tweet, or message, to other users. The symbol % means to divide by 100 in today s lesson.

3 Homework Questions?

4 When are we ever going to have to use percents? Accountant (C.P.A.), Advertising Account Exec., Architect, Assembler (Electronics), Attorney, Auto Body Repair Worker, Auto Mechanic, Bank Teller, Biologist, Business Planner, Camera Operator (TV), Carpenter, Ceramic Artist, Chef/Caterer, Chief Exec. Officer (Bank), Chief Financial Officer (Bank), Chiropractor, Comp. Programmer (Business/Real Time), Computer Systems Analyst, Computer Technician (Micros), Cosmetologist, Curator (Art Museum), Dentist (General), Dietician, Disease Registry Technician, Doctor (Internist), Electrician (Residential), Electronics Technician, Aerospace/ Air Quality/ Chemical/ Electronics/ Mechanical/ Microwave/ Process/ Quality Control/ Structural Engineer, Engineering Technician,

5 When are we ever going to have to use percents? Farm Operator, Financial Planner (Personal), Firefighter, Forest Ecologist, Forestry Technician, General Contractor, Golf Pro, Graphic Artist, Highway Patrol Officer, Homemaker, Instrument Tech (Air Quality), Insurance Agent, Interior Decorator, International Marketer, Landscaper Gardner, Librarian (Cataloguing), Machinist (Prototype), Market Researcher, Medical Lab Technologist, Medical Researcher, Motel Manager, Newspaper Reporter, Nurse, Optician, Optometrist, Painting Contractor, Paralegal, Payroll Supervisor, Personnel Manager, Pharmacist (Community), Physical Therapist, Physicist (Research), Plumber, Printer, Psychotherapist, Public Relations Director, Real Estate Agent, Recreation Supervisor, Restaurant Manager, Retail Salesperson, Road Maintenance Worker, Secretary (Administrative), Small Business Owner, Stock Broker, Surveryor (Land), Travel Agent, Urban Planner, Veterinarian, Wage/Salary Analyst, Waiter/Waitress, X-Ray Technician

6 Section 7.5 Percents

7 Objective I want to be able to work with percents and decimals.

8 Definition The word percent means hundredths or divided by 100. The symbol % is used to represent percent.

9 Example 1 Expressas a fractioninsimplest form. 36%

10 Example 2 Expressas a fractioninsimplest form. 180%

11 Example 3 Express as a fractioninsimplest form % 0.75%

12 Example 4 Express as a fractioninsimplest form % %

13 Example 5 Writeeach number as a percent. 7 x x 700 x %

14 Example 6 Writeeachnumber as a percent x x %

15 Example 7 48%of 125iswhat number?

16 Example 8 9is36%of what number? 36 9 x x

17 Example 9 What percent of 225is99? x x x

18 Example 10 Solve. 2.8x x 10(2.8 x) 10( x) 28x x x 6

19 Example 11 A dealer pays $5500for a car and wants to make a profit of 15%. What should be the selling price? Step1 :Find15%of $ The profit should be $825. Step 2 : Add the profit to the cost: $5500 $825 $6325 The sellingpriceshould be $6325.

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21 Section 7.6 Percent Problems

22 Objective I want to be able to solve problems involving percents.

23 Formulas percent of change 100 change inprice originalprice amount invested annual interest rate annual simpleinterest

24 Example 1 Alyce originally paid $6500 for a car 3 years ago. The same car costs $7400 today. What is the change in price? Find the change in price by subtracting $6500 from $7400. $ $6500 = $900 Therefore, the price increased $900.

25 Example 2 The Fergusons real estate taxes went from $1560 to $1638. What was the percent increase? Let x = the percent of increase. Percent of change = change in price 100 original price x = x = 7800 x = 5 There was a 5% increase.

26 Example 3 The number of registered voters in Franklin increased by 14% over last year. There are now 9633 registered voters. How many were there last year? Let x = the number of voters last year. Then 9633 x = the change in number of voters. Percent of change = change in number of voters 100 number of voters last year 14 = 9633 x 100 x 14x = x 114x = x = 8450 There were 8450 voters last year.

27 Example 4 Jerry has $8000 invested in stocks that give him a total annual income of $550. If part of the stocks pay 8% a year and the remainder of the stocks pay 6.5% a year, how much money is invested in the stocks at each rate? Let x = the amount invested at 8%. Then 8000 x = the amount invested at 6.5% Amount Invested Rate Interest x x 8000-x (8000-x)

28 Example 4 Continued 0.08x (8000 x) = [0.08x (8000 x)] = 1000(550) 80x + 65(8000 x) = 550,000 80x + 520,000 65x = 550,000 15x = 30,000 x = x = 6000 $2000 is invested at 8% $6000 is invested at 65%

29 CAUTION! Common Error: Multiplying Crazed Sometimes you may want to multiply everything in the equation, but you must restrain yourself! In example 4, 1000 is only multiplied to to get 65. It is NOT multiplied to 8000 x! The terms inside the parentheses remain the same!

30 Sage-N-Scribe ORAL EXERCISES pg #3 33 multiple of 3 pg. 317 #1 12 odd

31 Try These! Write as a fraction in simplest form % % 3. 48% of 250 is what number? is 9% of what number? 5. What percent of 60 is 150?

32 Try These! Write as a fraction in simplest form % 19/ % 27/ % of 250 is what number? is 9% of what number? What percent of 60 is 150? 250%

33 And these! Solve. 1. Hildi bought a sweater for $38.25 after it had been marked down 15%. What was the original price of the sweater?

34 And these! Solve. 1. Hildi bought a sweater for $38.25 after it had been marked down 15%. What was the original price of the sweater? $45

35 What about these? Complete the table. Item Original Price New Price Percent Increase Compact Disk Personal Computer $12 $15? $790? 12% Bicycle? $ %

36 What about these? Complete the table. Item Original Price New Price Percent Increase Compact Disk Personal Computer $12 $15 25% $790 $ % Bicycle $110 $ %

37 How about these? Complete the table. Item Original Price New Price Percent Increase DVD $9.90 $7.92? Skis $230? 8.5% Running Shoes? $ %

38 How about these? Complete the table. Item Original Price New Price Percent Increase DVD $9.90 $ % Skis $230 $ % Running Shoes $70 $ %

39 Clear your calculators! CTRL HOME B Take out your agendas! Copy down DUE DATES! Homework: Sections

40 Journal Entry TOPIC: Percent of Change Answer the following question: Describe the percent of change formula in your own words. Explain any questions you have about the formula.