system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: Why are anthropologists always so impressed about a society having the concept of zero? Why would it be so hard to think of, why do some cultures not develop the concept and what effect does that have on their society?
gpt
It's not that they understand the concept of nothingness that's impressive, it's having the mathematical wherewithal to deal with zero as a mathematical *number.*

For comparison, consider the number (1/2).

The concept of "a half" is extremely intuitive. The relationship between circles and semicircles, lines and their midpoints, symmetry, etc. all rely on "halfness."

...But it's another matter to be able to deal mathematically with questions like "What's five minus a half?" or "What's a half divided by three quarters?"

Similarly, although "nothingness" as a concept is fairly straightforward, zero the *number* has several special properties that are not at all straightforward to deal with. What's zero divided by zero?