Looking up for definition for whole numbers on Google yields a result which mentions:
The whole numbers are also called the positive integers (or the nonnegative integers, if zero is included).
I was suspicious about this answer and I decided to dig more into this. I found a Quora answer which mentions:
According to American middle and high school textbooks, the set of whole numbers includes all positive integers and 0, and not anything else. In this context negative numbers cannot be whole numbers. I have no clue as to the origin of this poor usage.
Professional mathematicians (researchers) tend to use the term whole numbers somewhat more informally as a synonym for integers, with “whole” meaning without fractional part. Certainly −1, −2, … have no fractional part so they are whole. This is consistent with German terminology where the formal name for integers is “ganze Zahlen”, which literally means whole numbers, as well as French terminology “nombre entier” (often simply “entier”), with entier being a cognate to the English “entire” in the sense of whole. The best way to avoid ambiguity is to be explicit about which integers you are referring to by applying the appropriate adjective to “integer”. “Integer” by itself includes positive, 0, and negative; positive integers means 1 and up; non-negative integers means 0 and up; negative integers means −1 and down; non-positive integers means 0 and down. Do not use the terms natural numbers and whole numbers.
However, be careful with the concepts of positive and negative (“positif” and “négatif”, respectively), as the French think of 0 as both positive and negative, whereas English, German, and many other languages regard 0 as neither positive nor negative.
Does anyone know why American textbooks decided to go this way?
I ask because I’m using American textbooks to study maths and now I’m more curious about incorrect things in them. Yet, this is the first thing I found.