What are whole numbers? They are simply counting numbers like 0, 1, 2, 3, and so on. Whole numbers are the numbers you'd list off the top of your head or count on your hands.

## What Are Whole Numbers and What Aren’t Whole Numbers?

The following numbers are a set of whole numbers:

As you can see none of these values are negative numbers. That's because aside from 0 (which is neither a negative nor a positive integer) all whole numbers must be positive numbers.

Numbers like 1 and 6.33 are not whole numbers because they have fractional parts and decimals.

### Whole Numbers vs. Real Numbers and Natural Numbers

There are many different types of numbers, including natural numbers and real numbers. So, let's identify the differences and similarities between whole numbers and these other number systems.

#### Whole Numbers vs. Natural Numbers

These two identifiers are extremely similar. In fact, all natural numbers are whole numbers. But because all natural numbers must be positive, the only whole number that isn't a natural number is 0.

#### Whole Numbers vs. Real Numbers

All whole numbers are real numbers, but not all real numbers are whole numbers. Real numbers can also be rational and irrational numbers. This means real numbers can be negative or non-negative integers, fractions, or even integers with a decimal part that goes on forever without repeating. Here are some examples of real numbers:

You’ll notice that 2 and 17 are whole numbers, but the other numbers in the list aren’t.

## What Is the Purpose of Whole Numbers?

The ability to define whole numbers and differentiate them from natural numbers is an essential part of math. Whole numbers like 0, 1, and 2 are the building blocks to understanding more complex number identifiers like real numbers, rational numbers, and irrational numbers. Rounding to the nearest whole number can also help you make calculations or do mental math more quickly.