How to Find the Percent of a Number

What is a Percent?

The word percent means out of a hundred. The symbol we use to indicate percent is “%”. A percent takes place of a fraction with a denominator of one hundred. For instance, instead of saying that twenty out of every hundred students prefer pens, we can say 20% of students prefer to use pens. Or, for a more useful example, instead of saying that you got 85 out of 100 on the history test, you instead say your score was 85%.

How Percents Relate to Others

We can also use a percentage to take place of a decimal and vice versa. To make a decimal into a percent, simply move the decimal over two places. So .40 becomes 40%. Simple, isn’t it? You can go backwards and move the decimal up to places and turn it back into .40.

Now that you know what a percent is and how we use it, we can go on to talking about how we find it.

How To Find the Percent of a Number

Let’s say you want to find 15% (fifteen percent) of 80.

So first, we’re going to write 15% as a decimal. Remember how to do that? Move the decimal over two places. Now we have .15.

Remember that the word ‘of’ means multiply. So really, what we’re being told to do is .15 multiplied by 80.

Write your problem out like so;


x 80

Now multiply it out.

5×0=0. 1×0=0

Then we have;


x 80


We put down our X for our new line. Then we multiply it out again.

5×8=40 (Carry your four!)

1×8=8 (Add your four.)

Then, like any time we are multiplying two digits, we add up the rows.



Our total comes out to .12 (remember that you have to put in your decimal! This is very important!)

Now we’re going to go look up at our .15. There are two number behind the decimal. We need to make sure we have two numbers behind the decimal and move our decimal accordingly.

Our final total comes out to; 12.0

The answer to our problem; 15% of 80 comes out to 12.

Go ahead and plug in some of your own numbers, and check your work with a calculator. If you don’t get it the first couple times, don’t worry. You’ll pick it up. Soon enough you’ll be able to figure out percentages in your head.

You will encounter percentages every day so you should take the time to learn how to use them. They’re used to figure out things like sales tax, how much to tip your waitress, and even your final grade. Now that you understand how to find them, you can appropriately pay out all those things, and make sure that your grades are correct.