Write down, if possible, the largest whole number.

Hint: First of all, learn about the whole numbers, and check whether it has the largest number.
Whole numbers are the numbers without fractions, they are also called as positive integers with zero included. Whole numbers cannot be written in the form of the fractional component in any way.

Complete step-by-step answer:
Generally, whole numbers start with zero (0). All natural numbers are whole numbers but all whole numbers are not natural numbers because whole numbers start with 0 and natural numbers start with one (1). As whole numbers start with zero and if we go on with the count, there is no end at a particular number. So, as there is no termination for the whole numbers, we cannot say the largest whole number and it is not possible.
We can identify the largest whole number if a set of groups of numbers or limited numbers is given.

Note: Any type of set of numbers either natural numbers, whole numbers, integers, or fractions, etc can never have a termination. So, we cannot say the largest number as it is not possible.
 In the set of whole numbers, every number has a preceding number except zero as zero is the smallest whole number. A fraction which can also be in the form of the decimal can be between any two whole numbers but cannot be a whole number. Whole numbers are the easiest way to understand and use to learn basic mathematical functions like addition, subtraction, multiplication, and division.