Percent: Who Doesn't Love a Sale? (Discounts!)

Contributor: Briana Pincherri. Lesson ID: 11413

Oh good, those sneakers I want are discounted! But do I have enough money to buy them? How much are they? Learn the two ways to calculate discounts so you can be a better shopper (candy not included)!

categories

Middle School

subject
Math
learning style
Visual
personality style
Lion, Otter
Grade Level
Middle School (6-8)
Lesson Type
Quick Query

Lesson Plan - Get It!

Audio:

Hurry! All the Halloween candy is selling for 75% off the original price. Now that's a bargain! How much would a jumbo bag of chocolate bars cost if the original price was $6.99?

Every day you get bombarded with commercials telling you about the best deals, emails advertising online discounts, and fliers in the mailbox urging you to "Buy now and save!"

Even a fun trip to mall can turn into a mathematical nightmare when you see your favorite store sporting a "% off" sign. How do you figure out how much more you can buy with the amount you have in your pocket? Do you know how to do the math to figure out the discounted price? This skill can transform you into the savvy shopper of your household!

At this point, if you have completed the previous Related Lessons in the Percentages series, found in the right-hand sidebar, you should be familiar with the concept of percent and how to solve for the part of a number, the percentage, or a whole entire number.

The word "percent" actually means "per hundred." If that doesn't ring a bell, you may want to jump back to the previous Related Lessons to review that information. If it sounds familiar (and easy!), then you are ready to complete this lesson and learn all about discounts.

So let's get started.

Let's say you walk into the local department store and a jersey for your favorite team is 40% off. The original price was $39.99. Do you know how much the shirt costs now?

To find the total, you can solve this problem in one of two ways. Let's look at both techniques:

Method 1 Method 2
  • Find what 40% off is, and then subtract from the total.
  • Decide what percentage of the price you are still paying; then multiply it by the total price.
  • Write the equation:
.40 • $39.99 = x
  • Ask yourself:
If the discount is 40% OFF, what percent are you still paying?
  • Multiply:
$16.00 = x
  • Write the equation:
100% - 40% = 60%
  • This means 40% off is $16.00 off the total.
  • Multiply the percent you are paying (60%) by the total price.
  • Subtract:
$39.99 - $16.00 = $23.99
  • Multiply:
.60 • $39.99 = $23.99
The shirt is now $23.99 on sale.

 

As you can see, both methods lead you to the same answer. You need to decide which method is easiest for you.

Method 1

  • Multiply the percent off by the total price (Reminder: Change the decimal to percent by moving the decimal left 2 places!).
  • Take that answer and subtract from the total price.
  • The difference is the sale price.

Method 2

  • Decide what percent you ARE paying by subtracting the discount from 100% (Example: If a discount is 40% off, then you are paying 60%. 100% - 40% = 60%).
  • Take the percent you are paying times the total price.
  • The quotient is the sale price.

What do you notice that is the same about both methods? What is different? Take a minute to discuss this with a teacher or parent.

The good news is they are both just two steps and will get you a correct answer. Since that is the case, you can pick your preferred method and use it moving forward.

Before you try a few problems to see how well you can spot a bargain, watch this short How to Solve Discount Problems : Math Solutions video to see another example completed:

Resource not working? Report issue.

 

Pick your favorite method to find discounts and get ready to use it in the Got It? section.

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