For example :
2 + 0 = 0 + 2 = 2 (Addition of 0 to a whole number)
– 5 + 0 = ... + ... = – 5 (Addition of 0 to an integer)
You will observ that when you add 0 to a whole number, the sum is again that whole number. This happens for integers and rational numbers also.
a + 0 = 0 + a = a, where a is a whole number
b + 0 = 0 + b = b, where b is an integer
c + 0 = 0 + c = c, where c is a rational number
Zero is called the identity for the addition of rational numbers. It is the additive identity for integers and whole numbers as well.