Percent Word Problems

1. • 1. Discuss HW
• 2. One-Step Word Problems
• 3. Multi-Step Word Problems
• 4. Special Types of Percent Problems
– Rate of Change
– Successive Percent
– Simple Interest
• Quiz on MONDAY 

2. • A state official predicts that 70% of the registered voters in
Montana will vote on election day. If there are 514,000
registered voters in Montana, how many are predicted to
vote?
Step 1: Understand the
question. “How many
registered voters are
predicted to vote?”
Step 2: What info do
you need? Use the % of
voters predicted to vote
and the number of
registered voters.
Step 3: Choose the
operation. What is 70%
of 514,000?

3. • Many percent • Common Percent
applications require Problems:
more than one step.
• Markup: Usually have to
add the amount of the
mark up to the original
price.
• Discount: usually have to
subtract the percent of
discount from the original
price

4. • Vic pays his supplier • 1. Find the markup.
$75 for a jacket. If he Change 40% to a
puts a 40% markup on fraction or a
the jacket, how much decimal, and multiply
does he charge a by $75.
customer for a jacket?
• 2. Add the markup to
the original price.

5. • A chair originally sold • 1. Find the amount of
for $130. It was on sale the discount. Change
at a 20% discount. Find 20% to a decimal or a
the sale price of the fraction.
chair.
• 2. Subtract the
discount from the
original price to find the
sale price.

6. • Max wants to buy a • 1. Find the whole (the
used car. He has saved price of the used car).
$1200, which is 40% of – Change 40% to a
the amount he needs. decimal, divide into the
How much more does part.
Max need to save?
• 2. Subtract the amount
he has saved from the
Whole to find out how
much more Max needs
to save.

7. • Mr. and Mrs. Allen are • Find the total amount
planning to buy a house the Allens must pay
that is listed at $146,000. the day they sign the
When they sign the contract.
contract, they must make
a down payment of 10%
of the listed price. They • (1) $18,760
also have to pay $2000 to
their lawyer, $8760 to • (2) $21,360
their real estate • (3) $24,260
agent, and $900 for other • (4) $25,360
expenses involved with
the purchase. • (5) $26,260

8. • Mr. and Mrs. Allen are • The commission the real
planning to buy a house estate agent receives is
that is listed at $146,000. what percent of the list
When they sign the price of the house?
contract, they must make
a down payment of 10%
of the listed price. They • (1) 3%
also have to pay $2000 to
their lawyer, $8760 to • (2) 5%
their real estate • (3) 6%
agent, and $900 for other • (4) 8%
expenses involved with
the purchase. • (5) 10%

9. • You calculate the rate of • RULE:
change when you want
to know if an amount • 1. Find the amount of
has gone up or down change (difference
over a period of time. between original and
new amount)
• Up over time = rate of • 2. Put the amount of
increase change over the original
• Down over time = rate amount. Simplify.
of decrease • 3. Multiply by 100%

10. • In a few months the • 1. Find the change
price of heating oil went
from $1.20 a gallon to
$1.80 a gallon. By what
percent did the price • 2. , simplify.
increase?
• 3. Multiply by 100%.

11. • Sam weighed 200 • 1. Find the change
pounds last year. He
went on a diet, and this
year he weighs 160
pounds. What percent • 2. , simplify
of his weight did Sam
lose?
• 3. Multiply by 100%

12. • Successive means “following after another”
• In General:
• 1. Find a percent of a number
• 2. Calculate a new amount
• 3. Find a percent of the new amount

13. • A color TV was listed at • 1. Both percents are
$280. For a Presidents’ based on the list
Day sale, a store offered price, so add them both
a 10% discount on all together.
appliances. The store
offered and additional
5% off the list price for
paying cash. How much • 2. Find that percent of
does a buyer save if she the list price.
gets the TV on sale and
pays cash?

14. • Interest is money that • Formula:
money makes.
• Interest = Principal x
• Earn = savings account rate x time
• Pay = borrow money
• Find the PART

15. • Find the interest on • 1. Change the percent
$800 at 6% annual to a decimal
interest for one year.
• 2. Plug into Interest
formula
• 3. Multiply

16. • Roger borrowed $6000 • 1. Change percent and rate to a
fraction
from his brother to make
home improvements.
Roger agreed to pay his
brother 8% annual
interest. How much did • 2. Plug into formula
Roger owe in 1 year 6
months.
• 3. Cancel and multiply
• 4. Add the interest to the original
principal.