How to Solve Discount Problems


Hi, my name is Marija, and today I'm gonna show you how to solve discount problems. So let's say that we have an item that is 20 percent off, and that item costs 30 dollars. The first way that we can solve this problem is we can find out what is 20 percent of 30 dollars, and then subtract that from the price. So to find 20 percent of 30 dollars we have to multiply 30 times point 20. So whenever you go to multiply a percent, you have to first change it into a decimal. And to change a percent to a decimal you take the decimal point and you move two spaces back. So 20 percent is the same as point 20. So now we multiply, two times zero is zero, two times three is six, and when you multiply decimals you have to move back the amount of decimal spaces that are in your problem, so we get six. So this six is not how much our item is going to cost, the six is how much money we are getting off of our item. So now we have to do 30 dollars minus six dollars, and when we do that we realize that our new price is now 24 dollars, okay? So the first way to do this problem is take 20 percent of 30, we get six, and now subtract those six dollars to find your new price. The other way that you can solve a discount problem is by saying to yourself okay, if 20 percent off is what I'm getting, that means that I'm actually paying 80 percent of the price. You write 100 percent of the price is the whole price, so if I'm getting 20 off, I must be paying 80. So method number two to doing this problem would be to say what is 80 percent of 30 dollars? And when I multiply this style, I'm going to get 24 in one shot. So this kind of saves you a step. So you can either find out 20 percent of 30 and then subtract it, or you can just find out 80 percent of 30 and you'll be done with the problem in one shot. And that is how you do discount problems.

Marija Kero graduated from the Pforzheimer Honors College at Pace University with a Bachelor's Degree in Mathematics and Adolescent Education.