How To Calculate Sale Price and Discounts
Discover the magic of percent changes! Join our adventure with exciting examples and interactive games on figuring out increases and decreases. Let’s explore together and make math fun!
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.
1. | In a boutique, a $14 scarf is marked, “20% off.” What is the sale price of the scarf? |
2. | In an electronics store, a $75 iPod is labeled, “Save 15%.” What is the sale price of the iPod? |
3. | What is the discount for the iPod in Exercise 2? |
4. | A $30 shirt is marked, “Get off.” What is the sale price of the shirt? |
5. | In a bicycle store, a $500 bicycle is marked, “Get a 30% discount.” What is the sale price of the bicycle? |