The Percent Proportion
Percent of Change/Percent Error
Sales Tax, Tips, Markup
Discount
Simple Interest
100
What percent of 50 is 18?
Let n% represent percent.
What is 36%?
100
Find the percent of change. Round to the nearest whole percent if necessary. State whether the percent of change is an increase or a decrease.
15 yards to 18 yards
Find the amount of change: 18 – 15 = 3
What is the percent of change is 20%?
Since the number of yards increased, this is a percent of increase.
100
Find the total cost to the nearest cent.
$58 bill; 20% tip
What is $69.60?
Method 1: Add the tip to the regular price.
Find the tip.
Add the tip to the regular price.
Method 2: Add the percent of the tip to 100%.
100% + 20% = 120%
The total cost is 120% of the bill.
100
Find the sale price to the nearest cent.
$64 jacket; 20% discount
What is the sale price of the jacket is $51.20?
Method 1: Subtract the discount from the regular price.
Find the discount.
Subtract the discount from the regular price.
Method 2: Subtract the percent of discount from 100%.
100% – 20% = 80%
The sale price is 80% of the regular price.
100
Find the simple interest earned to the nearest cent for the principal, interest rate, and time.
$640, 3%, 2 years
What is the interest paid after 2 years is $38.40?
200
12 is 90% of what number?
Let w represent the whole.
What is 13.3?
200
Find the percent of change. Round to the nearest whole percent if necessary. State whether the percent of change is an increase or a decrease.
$15.60 to $11.70
Find the amount of change: $15.60 – $11.70 = $3.90
What is the percent of change is 25%?
Since the amount of money decreased, this is a percent of decrease.
200
Find the total cost to the nearest cent.
$1,500 computer; 7% tax
What is $1,605?
Method 1: Add sales tax to the regular price.
Find the sales tax.
Add the sales tax to the regular price.
Method 2: Add the percent of tax to 100%.
100% + 7% = 107%
The total cost is 107% of the bill.
200
Find the sale price to the nearest cent.
$1,200 TV; 10% discount
What is the sale price of the TV is $1,080?
Method 1: Subtract the discount from the regular price.
Find the discount.
Subtract the discount from the regular price.
Method 2: Subtract the percent of discount from 100%.
100% – 10% = 90%
The sale price is 90% of the regular price.
200
Find the simple interest earned to the nearest cent for the principal, interest rate, and time.
$580, 2%, 6 months
What is the interest paid after 6 months is $5.80?
300
What number is 0.5% of 8?
Let p represent the part.
What is 0.04?
300
Find the percent of change.
29 students to 40 students
Find the amount of error by subtracting the estimate from the actual number of people.
300 – 230 = 70
What is 37.9% increase?
300
Find the selling price of a $270 bicycle with a 24% markup.
What is the price of the bike after the markup is $334.80?
Find the markup. Let m represent the markup.
part = percent × whole
m = 0.24 × 270
m = 64.80
Add the markup to the selling price.
$64.80 + $270 = $334.80
300
A bottle of hand lotion is on sale for $2.25. If this price represents a 50% discount from the original price, what is the original price to the nearest cent?
What is $4.50?
The sale price is 100% – 50% or 50% of the original price. Let p represent the original price.
300
Find the simple interest. Round to the nearest cent if necessary.
$2600, 5%, 4 years
What is the interest rate is $520?
400
Of the 60 books on a bookshelf, 24 are nonfiction. What percent of the books are nonfiction?
Let n% represent percent.
What is 40% of the books are nonfiction?
400
Find the percent of change for the situation. Round to the nearest whole percent if necessary. State whether the percent of change is an increase or a decrease.
Last school year the enrollment of Genoa Middle School was 465 students. This year the enrollment is 525.
Find the amount of change: 525 – 465 = 60
What is the percent of change is about 13%?
Since the enrollment increased, this is a percent of increase.
400
A restaurant bill comes to $28.35. Find the total cost if the tax is 6.25% and a 20% tip is left on the amount before tax.
What is the total restaurant bill is $35.79?
Sales tax is 6.25% and the tip is 20%, so together they will be 26.25%.
Add the tax and tip to the amount of the bill.
400
Find the sale price to the nearest cent.
$119.50 skateboard; 20% off; 7% tax
What is the sale price including tax is $102.29?
Find the discount.
Subtract the discount from the regular price.
The sale price of the skateboard is $95.60.
Find the sales tax.
Add the sales tax to the regular price.
400
Find the simple interest earned to the nearest cent for the principal, interest rate, and time.
$1,050, 4.6%, 2 years
What is the interest paid after 2 years is $96.60?
500
The types of flowers shown in the table make up an arrangement. What percent of the flowers in the arrangement are roses?
Write a proportion. Let n% represent the percent.
What is 60% of the flowers are roses?
500
Find the Error Dario is finding the percent of change from $52 to $125. Find his mistake and correct it.
What is the denominator should be $52?
The ratio should have had a denominator of $52, and the percent of change would be about 140%.
500
Toru takes his dog to be groomed. The fee to groom the dog is $75 plus 6.75% tax. Is $80 enough to pay for the service? Explain.
What is the total fee to groom the dog is $80.06, so $80 is not enough to pay for the service?
Method 1: Add sales tax to the regular price.
Find the sales tax.
Add the sales tax to the regular price.
Method 2: Add the percent of tax to 100%.
100% + 6.75% = 106.75%
The total cost is 106.75% of the bill.
500
Compare and contrast tax and discount.
500
Find the simple interest paid to the nearest cent for the loan amount, interest rate, and time.
$2,700, 8.2%, 3 months
What is the interest paid after 3 months is $55.35?