Why is zero a whole number?

Hint: This question is from the topic of algebra. The numbers 1, 2, 3,..... which we use for counting are known as natural numbers. If we add the number zero to the collection of natural numbers, we get the collection of whole numbers. Thus, the numbers 0, 1, 2, 3,....... is from the collection of whole numbers. Every whole number is a successor. Every whole number except zero has a predecessor.

Complete step by step solution:
In mathematics, natural numbers are ordinary whole numbers used for counting such as “there are 5 pens” and ordering such as “he is the \[{{4}^{th}}\] largest person in his family”.
There is no universal agreement about whether we should include zero in the set of natural numbers. Some define the natural numbers as the positive integers {1, 2, 3, 4, .....}, while some designates the number as non-negative integers {0, 1, 2, 3, 4, .....}. Some authors use the term ‘natural number’ to exclude zero and ‘whole number’ to include it. And, some other authors use ‘whole number’ in a way that excludes zero, or in a way that includes both zero and the negative integers.
The natural numbers had their origins in the words used to count things, beginning with the number 1.
In the early 700 BC, an idea was developed that zero can be considered as a number, with its own numeral. This idea was proposed by Babylonians, but they omitted such a digit when it would have been the last symbol in the number.
The use of a numeral zero in modern times originated with the Indian mathematician Brahmagupta in 628 AD.
It can be noted that many Greek mathematicians did not consider 1 to be ‘a number’, so to them 2 was the smallest number. Independent studies also occurred at around the same time in India, China, and Mesoamerica. Several set theoretical definitions of natural numbers and whole numbers were developed in the \[{{19}^{th}}\] century. With those definitions it was convenient to include 0 as a natural number.
And, from there we are presuming that the natural numbers along with zero are a collection of whole numbers.

Note: Some theories say that as 1 has no predecessor in natural numbers, so to the collection of natural numbers we add zero as the predecessor for 1. And, from we accepted 0 as a whole number.
All natural numbers are whole numbers, but all whole numbers are not natural numbers.
We can add two whole in any order. We can multiply two whole numbers with any order.
Some authors or mathematicians agreed on that whole numbers do not include fractions.