If you're seeing this message, it means we're having trouble loading external resources on our website.

If you're behind a web filter, please make sure that the domains *.kastatic.org and *.kasandbox.org are unblocked.

Lesson 2: Whole numbers & integers

# Whole numbers & integers

Walk through the difference between whole numbers & integers. For example, is the number -8 a whole number? Is it an integer?
First we'll learn about whole numbers, then we'll learn about integers, and we'll finish by thinking about whole numbers and integers at the same time.

## Whole numbers

Whole numbers are the numbers starting at $0$ and counting up forever:
$\left\{0,1,2,3,4,5,6,7,8,9,10,11\text{…}\right\}$
Key idea: Whole numbers don't include negative numbers, fractions, or decimals.
Is $8$ a whole number?

Is $9749$ a whole number?

Is $-5$ a whole number?

Is $9.5$ a whole number?

Is $\frac{5}{7}$ a whole number?

Sweet, let's move onto integers.

## Integers

Integers are just like whole numbers, but they also include negative numbers:
$\left\{\text{…}-5,-4,-3,-2,-1,0,1,2,3,4,5\text{…}\right\}$
Key idea: Like whole numbers, integers don't include fractions or decimals.
Is $\frac{1}{3}$ an integer?

Is $7$ an integer?

Is $-9$ an integer?

Is $8.6$ an integer?

Is $-8.6$ an integer?

Is $-947$ an integer?

Is $-\frac{1}{3}$ an integer?

Great, now that we've learned both whole numbers and integers, we're ready to classify numbers.

## Classifying numbers

What type of number is $-3$?
What type of number is $5.1$?
What type of number is $12$?