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 percentages—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.