In this intro to percentages lesson, you'll get a chance to fully understand them before calculating and converting them.

### What are percentages?

A **percentage** is another way of writing a decimal. Just like decimals, a percentage is a **part** of a **whole**. Basically, it's less than 1 whole thing, but more than 0.

We use percentages all the time in real life. For example, have you ever left a fifteen percent tip at a restaurant? Or bought something on sale for twenty percent off? Those are both percentagesâ€”15 percent and 20 percent.

Click through the slideshow to learn how percentages work.

Let's look at some more **percentages** from real life. In Introduction to Decimals, you learned that 25 cents is 0.25 of a dollar.

Another way to say this is that 0.25 cents is 25 percent of a dollar.

What about two quarters, or fifty cents? That's 0.50, or 50 percent of a dollar.

Three quarters would be 75 cents, or 75 percent of a dollar.

And four quarters, or 100 cents, would be 100 percent of a dollar...

And four quarters, 100 cents, would be 100 percent of a dollar...or one whole dollar.

Percent literally means **"per hundred"**, or **"out of a hundred****"**.

In our example, every dollar is made up of one hundred pennies, or 100 cents.

So you could say that each penny is equal to 1 percent of a dollar.

Let's look at another example. Let's imageine we cut a pizza into five slices.

Each slice is equal to one-fifth, or .20, of the pizza.

We know that one slice is equal to .20 because .20 + .20 + .20 + .20 + .20 = 1.00.

So we can also say that one slice is equal to 20 percent of the pizza.

We can use the **percent sign** (%) to write that as 20%.

Right now, we have one whole pizza, or 100% of the pizza.

What if we take away one slice? Now we have 80%. That's because we removed a slice, or 20% of the pizza.

What if we take away two slices? Now we have 60%.

Now we have 40% left.

Even though we have** less than one** pizza, we still have more **than zero pizzas**. We have a **percentage** of the pizza left.