1. 5-5 Simple Interest

2. Video Tutor Help Finding simple interestFinding simple interest (5-5) Simple Interest Khan Academy Simple interest

3. Video Tutor Help Writing percents as fractions Writing percents as decimals Writing decimals as percents Ordering rational numbers with percents Writing fractions as percents Finding a percent using proportions Finding part of a whole using proportions Find the whole amount using proportions Using percent equations to find part of a whole Using percent equations to find a whole amount Finding sales tax Estimating using percents such as tips Finding simple interest Finding percent of increase Finding percent of markup Finding percent of discount

4. Worksheets Daily Notetaking Guide Worksheets Version A Practice, Guided Problem Solving Lesson 5-5 Practice 5-5 Guided Problem Solving 5-5

5. Vocabulary Practice Vocabulary (Electronic) Flash Cards Ratios, Rates, and Proportions Vocabulary 5A: Graphic Organizer Vocabulary 5B: Reading Comprehension Vocabulary 5C: Reading/Writing Math Symbols Vocabulary 5D: Visual Vocabulary Practice Vocabulary 5E: Vocabulary C Vocabulary 5F: Vocabulary Review Puzzle

6. Additional Lesson Examples Step-by-Step Examples Lesson 5-5

7. Lesson Readiness Lesson Quiz Problem of the Day Lesson 5-5

11. Simple Interest Interest is the amount of money paid or earned for the use of money. For a savings account, you earn interest from the bank. For a credit card, you pay interest to the bank. To solve problems involving simple interest, use the following formula. I = prtI = prt Interest is the amount of money paid or earned. The annual interest rate should be expressed as a decimal. The principal is the amount of money invested or borrowed. The time is written in years.

13. Example 8-1a Find the simple interest for $2,000 invested at 5.5% for 4 years. Write the simple interest formula. Replace p with 2,000, r with 0.055, and t with 4. The simple interest is $440. Answer: $440 Find Simple Interest

14. Example 8-2a GRID-IN TEST ITEM Find the total amount of money in an account where $80 is invested at 6% for 6 months. You need to find the total amount in an account. Notice that the time is given in months. Six months is year. Read the Test Item Find the Total Amount

15. Example 8-2b Solve the Test Item The amount in the account is $80 + $2.40 or $82.40.

16. Find the simple interest on $500 invested at a 3% annual interest rate for 4 years. LESSON 5-5 The interest is $60. I = (500)(0.03)(4)Substitute. Use 0.03 for 3%. Write the formula. I = prt Simplify. = 60 Simple and Compound Interest Additional Examples

18. Example 7-5a Banking Suppose you invest $2000 at an annual interest rate of 4.5%. How long will it take for it to earn $495? Write the simple interest formula. Replace I with 495, p with 2000, and r with 0.045. Simplify. Apply Simple Interest Formula

19. Example 7-5b Divide each side by 90. Simplify. Answer:It will take 5.5 years to earn $495.

20. Graph the simple interest you earn on $500 at an annual rate of 3% over 4 years. LESSON 5-5 Step 2Draw a graph. Simple and Compound Interest Time (yr) 1 15 2 30 3 45 4 60 Step 1 Make a table. Let t = time. Interest ($) Additional Examples

23. You deposit $500 in a bank account that pays 3% interest compounded annually. What is your balance after 4 years? LESSON 5-5 Check for Reasonableness The compound interest is $562.75 – $500, or about $62.75. Simple interest would be I = ($500)(0.03)(4), or $60. Since compound interest is greater, the answer is reasonable. The balance after 4 years is $562.75 Write the formula. B = p(1 + r ) t Substitute. Use 0.03 for 3%. = 500(1 + 0.03) 4 Use a calculator to simplify the power. = 500(1.12550881) 562.75Round to the nearest cent. Simple and Compound Interest Additional Examples