1. Lesson 9 Menu Five-Minute Check (over Lesson 5-8) Main Idea and Vocabulary Targeted TEKS Example 1: Find Simple Interest Example 2: Find the Total Amount Example 3: Find the Interest Rate

2. Lesson 9 MI/Vocab interest principal Solve problems involving simple interest.

3. Lesson 9 Ex1 Find Simple Interest Find the simple interest for $2,000 invested at 5.5% for 4 years. I = prtWrite the simple interest formula. I = 2000 ● 0.055 ● 4Replace p with 2,000, r with 0.055, and t with 4. I = 440The simple interest is $440. Answer: $440

4. A.A B.B C.C D.D Lesson 9 CYP1 A.$160 B.$175 C.$215 D.$225 Find the simple interest for $1,500 invested at 5% for 3 years.

5. Lesson 9 Ex2 GRIDDABLE Find the total dollar amount in an account where $80 is invested at a simple annual interest rate of 6% for 6 months. Find the Total Amount Read the Test Item You need to find the total amount in an account. Notice that the time is given in months. Six months is year. Solve the Test Item I = prtSimple interest formula

6. Lesson 9 Ex2 I = 2.4Simplify. Answer: The amount in the account is $80 + $2.40 or $82.40. Find the Total Amount

7. Lesson 9 CYP2 1.A 2.B 3.C 4.D A.$60.30 B.$61.20 C.$62.20 D.$62.30 TEST EXAMPLE Find the total amount of money in an account where $60 is invested at 8% for 3 months.

8. Lesson 9 Ex3 LOANS Gerardo borrowed $4,500 from his bank for home improvements. He will repay the loan by paying $120 a month for the next four years. Find the simple interest rate of the loan. Use the formula I = prt. To find I, first find the total amount of money Gerardo will pay. $120 ● 48 = $5,760 He will pay $5,760 – $4,500 or $1,260 in interest. So, I = 1,260. The principal is $4,500. So, p = 4,500. The loan will be for 48 months or 4 years. So, t = 4. Find the Interest Rate

9. Lesson 9 Ex3 I = prtWrite the simple interest formula. 1,260 = 4,500 ● r ● 4Replace I with 1,260, p with 4,500, and t with 4. 1,260 = 18,000rSimplify. Answer: The simple interest rate is 7%. Find the Interest Rate Divide each side by 18,000. 0.07 = r

10. 1.A 2.B 3.C 4.D Lesson 9 CYP3 A.7.5% B.10% C.12% D.13.5% LOANS Jocelyn borrowed $3,600 from her bank for home improvements. She will repay the loan by paying $90 a month for the next five years. Find the simple interest rate of the loan.