When you buy an item on sale, the original price of the item has been reduced by some dollar amount. The discount rate, usually given as a percent, is used to determine the amount of the discount. To determine the amount of discount, we multiply the discount rate by the original price.
discount
An amount of discount is a percent off the original price.
The sale price should always be less than the original price. In some cases, the amount of discount is a fixed dollar amount. Then we just find the sale price by subtracting the amount of discount from the original price.
How To: Calculate Sale Price from a Discount
Understand the Terms:
Original Price: The price of the item before any discounts.
Discount Rate: The percentage by which the price is reduced.
Amount of Discount: The actual dollar amount that the price is reduced by.
Sale Price: The new price of the item after the discount is applied.
Calculate the Amount of Discount: Convert the discount rate from a percentage to a decimal by dividing by [latex]100[/latex]. Multiply the original price by the decimal discount rate.
Calculate the Sale Price: Subtract the amount of discount from the original price.
Jason bought a pair of sunglasses that were on sale for [latex]\text{\$10}[/latex] off. The original price of the sunglasses was [latex]\text{\$39}[/latex]. What was the sale price of the sunglasses?
Identify what you are asked to find.
What is the sale price?
Choose a variable to represent it.
Let [latex]s=[/latex] the sale price.
Write a sentence that gives the information to find it.
The sale price is the original price minus the discount.
Translate into an equation.
Simplify.
[latex]s=29[/latex]
Check if this answer is reasonable.
Yes. The sale price, [latex]\text{\$29}[/latex], is less than the original price, [latex]\text{\$39}[/latex].
Write a complete sentence that answers the question.
The sale price of the sunglasses was [latex]\text{\$29}[/latex].
Elise bought a dress that was discounted [latex]\text{35%}[/latex] off of the original price of [latex]\text{\$140}[/latex].
What was the amount of discount?
What was the sale price of the dress?
1. Before beginning, you may find it helpful to organize the information in a list.
Original price = [latex]\text{\$140}[/latex]
Discount rate = [latex]35\text{%}[/latex]
Amount of discount = ?
Identify what you are asked to find.
What is the amount of discount?
Choose a variable to represent it.
Let [latex]d=[/latex] the amount of discount.
Write a sentence that gives the information to find it.
The discount is [latex]35\text{%}[/latex] of the original price.
Translate into an equation.
Simplify.
[latex]d=49[/latex]
Check if this answer is reasonable.
Yes. A [latex]\text{\$49}[/latex] discount is reasonable for a [latex]\text{\$140}[/latex] dress.
Write a complete sentence that answers the question.
The amount of discount was [latex]\text{\$49}[/latex].
2.
Original price = [latex]\text{\$140}[/latex]
Amount of discount = [latex]\text{\$49}[/latex]
Sale price = ?
Identify what you are asked to find.
What is the sale price of the dress?
Choose a variable to represent it.
Let [latex]s=[/latex] the sale price.
Write a sentence that gives the information to find it.
The sale price is the original price minus the discount.
Translate into an equation.
Simplify.
[latex]s=91[/latex]
Check if this answer is reasonable.
Yes. The sale price, [latex]\text{\$91}[/latex], is less than the original price, [latex]\text{\$140}[/latex].
Write a complete sentence that answers the question.
The sale price of the dress was [latex]\text{\$91}[/latex].
