Discount and Sale Price

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Discount and Sale Price

Unit 10 > Lesson 2 of 9

Problem:	In a video store, a DVD that sells for $15 is marked "10% off." What is the discount? What is the sale price of the DVD?

Analysis:	Stores often sell goods for a discounted price. Typically, a store will discount an item by a percent of the original price. In this problem, an item that originally costs $15 is being discounted by 10%. So "10% off" refers to the rate of discount. To solve this problem, we need a procedure.

Procedure:

The rate is usually given as a percent.
To find the discount, multiply the rate by the original price.
To find the sale price, subtract the discount from original price.

Now that we have a procedure, we can solve the problem above.

Problem:

In a video store, a DVD that sells for $15 is marked, "10% off". What is the discount? What is the sale price of the DVD?

Solution:

The rate is 10%.

The discount is: 0.10 x $15.00 = $1.50

The sale price is calculated as follows:

$15.00		original price
- 1.50		- discount
$13.50		sale price

Answer:

The discount is $1.50 and the sale price is $13.50.

Let's take a look at some more examples of calculating discount and sale price.

Example 1:

In a department store, a $40 dress is marked, "Save 25%." What is the discount? What is the sale price of the dress?

Analysis:

The phrase, "Save 25%," refers to the rate.

The original price of the dress is $40.

Solution:

The rate is 25%.

The discount is: 0.25 x $40.00 = $10.00

The sale price is calculated as follows:

$40.00		original price
- 10.00		- discount
$30.00		sale price

Answer:

The discount is $10.00 and the sale price is $30.00.

Example 2:

In a grocery store, a $12 case of soda is labeled, "Get a 20% discount." What is the discount? What is the sale price of the case of soda?

Analysis:

The phrase, "Get a 20% discount," refers to the rate.

Solution:

The rate is 20%.

The discount is: 0.20 x $12.00 = $2.40

The sale price is calculated as follows:

$12.00		original price
- 2.40		- discount
$ 9.60		sale price

Answer:

The discount is $2.40 and the sale price is $9.60.

Example 3:

In a candy store, a $5.00 jar of candy is labeled, "50% off." What is the discount? What is the sale price of the jar of candy?

Analysis:

The phrase, "50% off," refers to the rate.

Solution:

The rate is 50%.

The discount is: 0.50 x $5.00 = $2.50

The sale price is calculated as follows:

$5.00		original price
- 2.50		- discount
$2.50		sale price

Answer:

The discount is $2.50 and the sale price is $2.50.

In Example 3, note that the discount and the sale price are the same amount! Do you know what fraction is equal to 50%? Could you have done this problem using mental math? The phrase, "50% off," is the same as, "1/2 off". So using mental math, you would get that one-half of $5.00 is $2.50. Let's look at another example that uses a fraction.

Example 4:

A pizzeria has a coupon that reads, "Get

off a $9.00 cheese pizza." What is the discount? What is the sale price of the cheese pizza?

Analysis:

The phrase, "

off," refers to the rate. It is expressed as a fraction.

Solution:

The rate is given as the fraction

The discount is:

x $9.00 = $3.00

The sale price is calculated as follows:

$9.00		original price
- 3.00		- discount
$6.00		sale price

Answer:

The discount is $3.00 and the sale price is $6.00.

Once again, you could calculate the discount and sale price using mental math. Let's look at another way of calculating the sale price of an item. Below is a modified version of the problem from the top of this page.

Example 5:	In a video store, a DVD that sells for $15 is marked, "10% off." What is the sale price of the DVD?
Solution:	The rate is 10%. Thus, the customer is paying 90% for the DVD.
	The sale price is: 0.90 x $15.00 = $13.50

Answer:	The sale price is $13.50.

Note that we calculated the sale price in the above problem, but we did not calculate the discount.

Summary:

Stores often sell goods for a discounted price. Typically, a store will discount an item by a percent of the original price. The rate of discount is usually given as a percent, but may also be given as a fraction. The phrases used for discounted items include, "

off," "Save 50%," and "Get a 20% discount."

Procedure:

To calculate the discount, multiply the rate by the original price.
To calculate the sale price, subtract the discount from original price.

Exercises

Directions: Solve each problem below by entering a dollar amount with cents. For each exercise below, click once in the ANSWER BOX, type in your answer and then click ENTER. After you click ENTER, a message will appear in the RESULTS BOX to indicate whether your answer is correct or incorrect. To start over, click CLEAR.