In elementary school in a Dutch-speaking country, we were taught the concepts of $\mathbb {N}$, the set of "natuurlijke getallen" ("natural numbers") and $\mathbb {Z}$, the set of "gehele getallen" ("whole numbers"). At no point was there ever a hint that these terms were not unequivocal.

In elementary school in a Dutch-speaking country, we were taught the concepts of $\mathbb {N}$, the set of "natuurlijke getallen" ("natural numbers") and $\mathbb {Z}$, the set of "gehele getallen" ("whole numbers"). At no point was there ever a hint that these terms were not unequivocal.

I remember $\mathbb {Z}$ and $\mathbb {N}$ then being used as examples to teach Venn diagrams, at which point it was emphasized again that the difference between the two sets was the negative numbers.