Prime And Composite Numbers

 

Prime Number: A number other than 1 whose only factors are 1 and the number itself is called a Prime number.   When a number cannot be divided up evenly it is a Prime Number.

Example: 2, 3, 5, 7, 11

Composite Number: A number having more than two factors is called  a Composite number (i.e) which has factors other than 1 and itself. When a number can be divided up evenly it is a Composite Number.

 

Demonstration:

Is  7 a Prime Number or Composite Number?

We cannot divide 7 evenly by 2 (we get 2 lots of 3, with one left over)

We cannot divide 7 evenly by 3 (we get 3 lots of 2, with one left over)

We cannot divide 7 evenly by 4, or 5, or 6.

We can only divide 7 into one group of 7 (or seven groups of 1): 7 = 1 x 7
So 7 can only be divided evenly by 1 or itself: So 7 is a Prime Number

Is 6 a Prime Number or Composite Number?

6 can be divided evenly by 2, or by 3, as well as by 1 or 6:

6 = 1 × 6
6 = 2 × 3

So 6 is a Composite Number