[miobrien]

This reminds me of a question from my first interview as a college grad: estimate the number of taxis in New York City. I was totally baffled by it.

[singleshot_]

I’ll simplify for manhattan and extrapolate for the four outer boroughs. Ten avenues, a hundred streets. A thousand blocks? One cab per block? One thousand cabs in manhattan? 5,000 total?

There are about 13,500 taxi medallions.

[saghm]

That sort of estimation feels a lot easier to me than the "golf balls in a baseball stadium one" that was mentioned by the parent because it's dealing with quantities I can recall having heard before like "how many streets are there in Manhattan" rather than measurements that personally would never stick in my head like "how wide is a golf ball". I'm not sure why, but I've always been awful at making even rough estimates of units. If you gave me the diameter of a golf ball and the dimensions of the stadium, I could do some basic calculations, but even though I physically know about how large a golf ball is, I couldn't tell you whether it's more likely that its diameter is 0.5 or 1.5" (and not having looked it up, I would believe you if you told me it wasn't even within that range)! This gets worse with units I can't visualize (like weight), and when the sizes get larger than I can easy relate to; if you asked me questions like how much a car weighs or how long the Brooklyn Bridge is, I'm doubtful I'd even be within a factor of 2 more often than not.

I'm probably taking this more seriously than it was intended above, but the idea that this is some sort of proxy for "thinking" or "intelligence" feels off to me; doing the math given the size of something might be thinking or intelligence, but knowing roughly "how big" something is seems more like intuition.

[Breza]

I had a great boss who really liked that kind of question. I disagreed with him. I would rather have someone who knows how to find the official answer online and verify the quality of the source.

[kragen]

A crucial tool for verifying the quality of the source is noticing when the answers given by the source are clearly wrong by orders of magnitude.

[nocoiner]

Ideally I think the ability to come up with a quick off-the-cuff guess that is correct to one order of magnitude and then find and verify the specific answer are nicely complementary.