Chapter 5 - Number Theory and the Real Number System - 5.5 Real Numbers and Their Properties; Clock Addition - Exercise Set 5.5 - Page 308: 5

0

0 is a whole number that is not a natural number because the natural numbers start at 1 and go to infinity in whole number increments. Natural numbers are symbolized like this: N = {1, 2, 3, 4, 5, ...} Whole numbers start at 0 and then proceed just like the natural numbers. 0 is the only whole number that is not also a natural number.