IXL | Simple interest | 7th grade math

Tom
has
$400
in
a
savings
account
that
earns
5
%
interest
per
year.
The
interest
is
not
compounded.
How
much
will
he
have
in
total
in
1
year?

Use the formula i = prt, where i is the interest earned, p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years.

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question

Erik
has
$500
in
a
savings
account.
The
interest
rate
is
10
%
per
year
and
is
not
compounded.
How
much
will
he
have
in
total
in
1
year?

Use the formula i = prt, where i is the interest earned, p is the principal (starting amount), r is the interest rate expressed as a decimal, and t is the time in years.

key idea

i = prt

i	is the interest earned

p	is the principal (starting amount)

r	is the interest rate expressed as a decimal

t	is the time in years

To find the total amount in an account, calculate the interest and then add it to the principal.

solution

Write the rate as a decimal.

0.1

Calculate the interest earned.

$500

0.1

$50

Find the total amount by adding the interest to the principal.

$50 + $500 = $550

The total amount will be $550.

Looking for more? Try these:

Lesson: Simple interest

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O.8Solve percent equations

D.1Add and subtract decimals

Lesson: Simple interest

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