Prime numbers refer to numbers that are greater than 1 and can only be divided evenly and with itself.  After division, the separate entities must be even and must not contain additional decimals or fractions.  Numbers that cannot be divided evenly and are greater than 1 also are classified as composite numbers.

Knowing which numbers are prime numbers could be an easy task for people who like the subject of mathematics.  For many of these people, solving equations and creating formulas are not complicated for them and it will only take them a short time to handle math problems.  For other people, a simple issue of knowing if a number is prime or composite, is definitely no easy task.  The fact that numbers are involved make people think of the problem or concern as very difficult.  With this concern at hand, many teachers and math experts try to teach their students with different techniques in knowing about prime numbers and composite numbers.  For those who find ease with the math subject, they can employ factorization when trying to find out if a number is indeed a prime number or not.  Through factorization, people will be able to get the factors or divisors for a particular number.  Prime numbers will only have two divisors including itself and so for numbers that have more divisors, they automatically become composite numbers.

For people who are not so math-savvy, they may be taught about prime numbers through the concept of separating piles or items.  Using coins for example, students may be asked to divide the coins into two even halves.  If there are remainder coins involved, then the division is not even and therefore the number involved is not prime.  If the same number can be divided into 3 different groups for example, it simply means that this number is also not a prime number.  The basic rule for prime number is that it can only be divided by itself or evenly.  More than two divisors involved makes a number become composite instead of prime.