Existence of additive identity

Property 4 (Existence of addition identity): There is integer 0such that for any integer am we have a+0=a=0+a The integer 0 is called the additive identity.

Existence of additive inverse

Property 5 (Existence of additive inverse): For every integer a there exists its opposite -a such that Integers a and -a are called opposites or negative or additive inverse of each other.

The whole number 0 (zero) is called the additive identity or the identity element for addition of whole numbers.

What is the additive identity of rational number?

What is the additive identity for whole numbers?

Existence of negative (additive inverse) of a rational number

ul("R") is the additive identity of whole numbers.