# How to find out what a number is a percentage of another number?

A percentage is an important tool in mathematics, employed to know the certain ratio in a concise form.

## Answer: To find out how much a number(A) is a percentage of another number (B), we can use the formula: A/B × 100%.

Go through the examples to understand the basic idea behind this calculation.

**Explanation:**

Let’s assume that you need to find what percentage x is of y.

We can make use of x / y. The number that comes after the word “of” is always the denominator, while the other is the numerator.

Once you have got your fraction, you must convert it to a percentage. There are two ways of doing this.

1) One is to get the fraction to be equal to a number over 100. So, z / 100 for instance. The numerator is the percentage. So, z / 100 = z %.

2) Another way is to divide the numbers with long division. Once you get your answer, you multiply it by 100. The product is the percentage.

Let’s try a problem.

What percentage of 10 is 3?

The number that comes after “of” is 10 so that will be our denominator. The other number is 3, so that will be our numerator. Now we get 3 / 10.

We have two ways to get our answer. Let’s do it by dividing. 3 divided by 10 is 0.3. 0.3 times 100 is 30. So 3 is 30 % of 10.

The other way is to make our denominator 100. We can multiply both numerator and denominator by 10 to get 30 / 100. Since the denominator is 100, the numerator is the percentage. So we now have 30 %. It is better to divide since you won’t always have a denominator that can become 100.