Percentages are a way of talking about parts of a whole. The word “percent” comes from Latin and literally means “per hundred.” So, when you see a number with a percent sign (%), it’s just a shorthand for saying “out of 100.”

If you ate 50% of a pizza, you ate 50 out of every 100 pieces. If a battery is at 25% charge, it has 25 units of energy for every 100 it can hold. It’s a universal way to compare parts of things, no matter how big the “whole” is.

To figure out a percentage, you need to know two things: the part you're interested in and the whole amount. The formula is straightforward.

Let's try an example. Imagine you're taking a quiz with 20 questions, and you answer 17 of them correctly. The "part" is 17, and the "whole" is 20. Let's plug those numbers into the formula.

So, you scored 85% on the quiz.

Percentages, fractions, and decimals are like different languages that express the same idea. Being able to convert between them is a useful skill. Here’s a quick guide.

Let's walk through one more. How would you write the fraction $\frac{2}{5}$ as a percentage?

First, convert the fraction to a decimal by dividing the numerator by the denominator: $2 \div 5 = 0.4$.

Next, convert that decimal to a percentage by multiplying by 100: $0.4 \times 100 = 40\%$. So, $\frac{2}{5}$ is the same as 40%.

Understanding these basics allows you to handle percentages in many different situations.