You have to define what a "whole number" is first, and that is a philosophical question. You may think it's obvious [1] what a "whole number" is and how it behaves under addition, but to make it formal you have to write it down. Pretty philosophical if you ask me.
[1] everyone though that, until a few smart logicians showed up in XXth century and proved everyone else wrong.
The effect of a brick falling on someone’s head is not a philosophical question, and neither is one about the common that clearly exists between, say, three horses and three apples you want treat these horses with.
[1] everyone though that, until a few smart logicians showed up in XXth century and proved everyone else wrong.