Today's size: guess the order of magnitude

A counting question appears and you type a number. You do not have to land on it: any answer within half of the right one counts as right, because the game is about the size and not the digits.

You get four tries, everyone gets the same question today, and it changes at midnight UTC.

Not quite, and the difference is deliberate. A real Fermi question asks about the world, and an answer about the world has to be defensible: 365 of those written by hand would be 365 numbers nobody could stand behind.

So the question stays about size and the answer became exact, coming from plain arithmetic. Nothing on screen is invented, and estimating the size without doing the calculation is still the whole game.

Because asking for the exact figure would be asking you to do the combinatorics in your head. Half either way is a wide net on purpose.

Nothing stops you, and it would give you the exact answer. It would also skip the only interesting part, which is finding out how far off your instinct was.

Not within the year. There are nine families of question and each day gets a different combination of numbers, checked so no two days are identical.

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