Simple Definition of a Prime Number
Suppose you have a set of objects and I ask you to divide them into subsets of equal size. The key thing here is "equal size".
This can often be done. But there are some sets where it cannot be done.
When it cannot be done we call the number of objects in the set a prime number.
Example: A set of 12 objects can be divided into subsets of equal size (actually, in several different ways), so 12 is not a prime number. A set of 13 objects can never be divided into subsets of equal size so 13 is a prime number.
Content written and posted by Ken Abbott firstname.lastname@example.org