Zero is therefore called the identity element for addition and subtraction.

If 0 is multiplied by any number, the product is 0.

If 0 is divided by any number (other than 0), the quotient is 0.

Division by 0 is not defined because it has no meaning.

If any number is multiplied or divided by 1, the number remains unchanged.

One is therefore called the identity element for multiplication and division.

The number zero and one are

**neither prime nor composite**.

So 2 would be the first prime number and 4 would be the first composite number