5–9 Simple Interest - 8th Grade Flipped Mastery...
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Math Connects, Course 3 137 Copyright © Glencoe/McGraw-Hill, a division of The McGraw-Hill Companies, Inc. 5–9 Simple Interest Interest is the amount of money paid or for the use of money. Principal is the amount of money or borrowed. BUILD YOUR VOCABULARY (pages 116–117) EXAMPLE Find Simple Interest Find the simple interest for $2,000 invested at 5.5% for 4 years. I = prt Write the simple interest formula. I = · · Replace p with , r with , and t with . I = The simple interest is . EXAMPLE Find the Total Amount TEST EXAMPLE Find the total dollar amount in an account where $80 is invested at a simple annual interest rate of 6% for 6 months. A $41.20 B $82.40 C $84.80 D $108.80 Read the Item You need to find the total amount in an account. The time is given in months. Six months is 6 _ 12 or year. Solve the Item I = prt I = · · I = The amount in the account is $80 + or . The correct answer is choice . MAIN IDEA • Solve problems involving simple interest. REMEMBER IT The t in the simple interest formula represents time in years. If time is given in months, weeks, or days, the time must be changed to time in years.
Transcript of 5–9 Simple Interest - 8th Grade Flipped Mastery...
Math Connects, Course 3 137
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.5–9 Simple Interest
Interest is the amount of money paid or for the use of money.
Principal is the amount of money or borrowed.
BUILD YOUR VOCABULARY (pages 116–117)
EXAMPLE Find Simple Interest
Find the simple interest for $2,000 invested at 5.5% for 4 years.
I = prt Write the simple interest formula.
I = · · Replace p with , r
with , and t with .
I = The simple interest is .
EXAMPLE Find the Total Amount
TEST EXAMPLE Find the total dollar amount in an account where $80 is invested at a simple annual interest rate of 6% for 6 months.
A $41.20 B $82.40 C $84.80 D $108.80
Read the Item
You need to fi nd the total amount in an account. The time is
given in months. Six months is 6 _ 12
or year.
Solve the Item
I = prt
I = · ·
I =
The amount in the account is $80 + or .
The correct answer is choice .
MAIN IDEA
• Solve problems involving simple interest.
REMEMBER IT The t in the simple interest formula represents time in years. If time is given in months, weeks, or days, the time must be changed to time in years.
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5–9
138 Math Connects, Course 3
Copyright ©
Glencoe/M
cGraw
-Hill, a division of T
he McG
raw-H
ill Com
panies, Inc.Check Your Progress
a. Find the simple interest for $1,500 invested at 5% for 3 years.
b. Find the total amount of money in an account where $60 is invested at 8% for 3 months.
EXAMPLE Find the Interest Rate
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 fi nd I, fi rst fi nd the total amount of money Gerardo will pay.
$120 · 48 = .
He will pay - $4,500 or in interest. So I = 1,260.
The principle is $4,500. So, p = 4,500. The loan will be for 48 months or 4 years. So, t = 4.
I = p · r · t
= · r ·
= Simplify.
= Divide each side by 18,000.
= r Simplify.
The simple interest rate is .
Check Your Progress Jocelyn borrowed $3,600 from her bank for home improvements. She will repay the loan by paying $90 a month for the next 5 years. Find the simple interest rate of the loan.
HOMEWORKASSIGNMENTPage(s):
Exercises:
ORGANIZE ITExplain what you have learned about computing simple interest. Be sure to include the simple interest formula.
Lesson 5-9
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