Lesson%209.7:%20Simple%20Interest

1
Lesson 9.7 Simple Interest

• ALCOS 3, 5, 6
• Objective Students will use the simple interest
  formula to calculate simple interests.

2
If someone borrows money, what factors
influence how much is paid back?
Principal -
How much was borrowed.
Time -
How long it was borrowed for.
(in years)
Rate -
What interest was charged.
(annual rate)
Amount to Payback
Principal

Interest
Interest
Principal
Rate
Time
3
Joe borrows 200 from the bank at 6
simple interest for 3 years. What interest does
he owe, and what is his total balance (amount to
payback)?
Interest
Balance
Balance
P

I
Balance
200

36
Balance 236
Balance 236
4
Juan invests 5000 in bonds for 6 months at
an annual interest rate of 7. How much
interest did he earn, and what is the balance in
his account?
Interest
Balance
Balance
P

I
Balance
5000

175
Balance 5175
Balance 5175
5
Find the simple interest and the balance.
Balance
P

I
Balance
2000

60
Balance 2060
6
Find the annual simple interest rate.
7
Find the annual simple interest rate.
8
Find the principal amount invested.