## The Lesson

A prime number is a number that can be divided by only itself and 1. For example,
• 2 is a prime number. It can only be divided exactly by 1 and 2 itself.
• 3 is a prime number. It can only be divided exactly by 1 and 3 itself.
• 4 is not a prime number. It can be divided exactly by 1, 2 and 4.

## Dictionary Definition

The Oxford English Dictionary defines a prime number as "a number that cannot be divided by any whole number (without a remainder) other than itself and one."

## The Prime Numbers

The prime numbers are: In a number square, the prime numbers are shaded below: These are just the prime numbers under 100. There are infinitely many prime numbers, they go on forever.

## Prime Numbers Are Natural Numbers Greater Than 1

Prime numbers are natural numbers (the counting numbers: 1, 2, 3...) greater than 1. 1 is not a prime number, even though it can only be divided by 1 and itself. Some times in history is has been considered a prime number, but now it is not.

## Interactive Game on Prime Numbers  