## Introduction

If you’re looking for the answer to the question “21 is what percent of 30,” you’ve come to the right place. This article will explain how to calculate percentages and show you step-by-step how to determine what percentage 21 is of 30.

## What is a Percentage?

Before we can determine what percentage 21 is of 30, it’s important to understand what a percentage is. A percentage is a way of expressing a number as a fraction of 100. For example, 50% means 50 out of 100, or 0.5 as a decimal.

## Calculating Percentages

To calculate a percentage, simply divide the part by the whole and multiply by 100. For example, if you want to find out what percentage 21 is of 30, you would divide 21 by 30 and then multiply by 100.

### Step-by-Step Calculation

To calculate what percentage 21 is of 30:

Step 1: Divide 21 by 30

21 ÷ 30 = 0.7

Step 2: Multiply by 100

0.7 × 100 = 70

Therefore, 21 is 70% of 30.

## Why Percentages are Important

Percentages are used in many different areas of life, including finance, science, and medicine. They are a useful tool for comparing different values and understanding relationships between them. For example, if you want to compare the performance of two stocks, you can use percentages to calculate their returns over a certain period of time.

## Conclusion

In conclusion, calculating percentages is a useful skill that can be applied to many different areas of life. If you’re wondering what percentage 21 is of 30, simply divide 21 by 30 and multiply by 100 to get the answer of 70%. Remember that percentages are a way of expressing a number as a fraction of 100, and they can be used to compare different values and understand relationships between them.