I see natural numbers as an abstraction for counting things. Like "3" is what "3 apples", "3 cars", "3 stars" have in common. In that sense, "0" doesn't have a

I see natural numbers as an abstraction for counting things. Like "3" is what "3 apples", "3 cars", "3 stars" have in common. In that sense, "0" doesn't have a different status. I find it more difficult to explain "-1". Probably using a position along an axis with an origin, which gives you all the real numbers.