Question

which is  the  smallest  whole number?

Answer 1

A whole number is a number which can be represented by a plain digit. 0 is a whole number as well. 

If we went for a definition we would say that whole numbers are a group of Natural numbers $[1,2,3,4,...,infinity]$, their opposite numbers $[-1,-2,-3,-4,...,-infinity]$ and zero.

Therefore, there is no smallest whole number because we cannot measure it. 

Cheers! :) 

Answer 2

the smallest whole number is zero! whole numbers starts from {0,1,2,3.... and so on!} there are no fractions or decimals.