## Learn About Calculating Percent Increase And Decrease With The Following Examples And Interactive Exercises.

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

analysis : Stores much sell goods for a discount price. typically, a storehouse will discount an item by a percentage of the master price. In this trouble, an item that in the first place costs $ 15 is being discounted by 10 %. So “ 10 % off ” refers to the rate of discount. To solve this problem, we need a routine .

**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 operation, we can solve the trouble above .

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

solution : The pace 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 rebate and sale price .

Example 1 : In a department store, a $ 40 full-dress is marked, “ Save 25 %. ” What is the dismiss ? What is the sale monetary value of the dress ?

analysis : The give voice, “ Save 25 %, ” refers to the rate .

The original monetary value of the dress is $ 40 .

solution : The rate is 25 % .

The dismiss is : 0.25 adam $ 40.00 = $ 10.00

The sale price is calculated as follows :

$40.00 | original price |

– 10.00 |
– discount |

$30.00 | sale price |

answer : The dismiss is $ 10.00 and the sale price is $ 30.00 .

Example 2 : In a grocery store, a $ 12 case of sodium carbonate is labeled, “ Get a 20 % deduction. ” What is the discount ? What is the sale price of the lawsuit of sodium carbonate ?

analysis : The phrase, “ Get a 20 % discount rate, ” refers to the rate .

solution : The rate is 20 % .

The discount is : 0.20 adam $ 12.00 = $ 2.40

The sale price is calculated as follows :

$12.00 | original price |

– 2.40 |
– discount |

$ 9.60 | sale price |

suffice : The rebate is $ 2.40 and the sale price is $ 9.60 .

Example 3 : In a candy memory, a $ 5.00 jar of candy is labeled, “ 50 % off. ” What is the rebate ? What is the sale price of the jar of candy ?

analysis : The phrase, “ 50 % off, ” refers to the rate.

solution : The pace is 50 % .

The deduction is : 0.50 ten $ 5.00 = $ 2.50

The sale price is calculated as follows :

$5.00 | original price |

– 2.50 |
– discount |

$2.50 | sale price |

answer : The deduction is $ 2.50 and the sale price is $ 2.50 .

In Example 3, note that the discount and the sale price are the same sum ! Do you know what fraction is peer to 50 % ? Could you have done this problem using genial mathematics ? The idiom, “ 50 % off, ” is the same as, “ 1/2 off ”. So using genial mathematics, you would get that one-half of $ 5.00 is $ 2.50. Let ‘s look at another exemplar 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 tall mallow pizza ?

analysis : The idiom, “ off, ” refers to the rate. It is expressed as a fraction .

solution : The pace is given as the fraction .

The rebate 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 dismiss is $ 3.00 and the sale price is $ 6.00 .

once again, you could calculate the rebate and sale price using mental mathematics. Let ‘s front at another way of calculating the sale monetary value of an detail. Below is a modified adaptation 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 monetary value of the DVD ?

solution : The rate is 10 %. therefore, the customer is paying 90 % for the DVD .

The sale price is : 0.90 ten $ 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 deduction .

summary : Stores much sell goods for a dismiss price. typically, a memory will discount an detail by a percentage of the original price. The rate of deduction is normally given as a percentage, but may besides be given as a divide. The phrases used for discount items include, “ off, ” “ Save 50 %, ” and “ Get a 20 % dismiss. ”

**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 total 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 right or faulty. To start over, snap CLEAR .

1. |
In a boutique, a $14 scarf is marked, “20% off.” What is the sale price of the scarf?ANSWER BOX: $ RESULTS BOX : |

2. |
In an electronics store, a $75 iPod is labeled, “Save 15%.” What is the sale price of the iPod?ANSWER BOX: $ RESULTS BOX : |

3. |
What is the discount for the iPod in Exercise 2?ANSWER BOX: $ RESULTS BOX : |

4. |
A $30 shirt is marked, “Get off.” What is the sale price of the shirt?ANSWER BOX: $ RESULTS BOX : |

5. |
In a bicycle store, a $500 bicycle is marked, “Get a 30% discount.” What is the sale price of the bicycle?ANSWER BOX: $ RESULTS BOX : |