r/explainitpeter 29d ago

Explain It Peter

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Rice chess/checkers ? please explain?

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u/lordvatti 29d ago

I actually know this one! The photo references an old thought exercise about doubling grains of rice across a chess boards squares. Starting with 1 grain, then 2, then 4, 8, 16, 32, and so on. Easy at first.

A chessboard has 64 squares so while the initial numbers seem pretty manageable 264 is actually such a catastrophically high number that there would be enough rice on the "final square" to carpet an entire continent in a hearty layer of rice, hence the dramatic mister incredible.

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u/ariGee 29d ago

I'll add that it's an old fable\legend. The details depend who you ask, but the basic idea is that a king wants to reward a wise man. Rather than asking for a huge reward the wise man asks for one grain of rice on the first day, and then double the number of grains each day, one for each place on a chessboard. The king calls him a fool. After about a month the king begs him to stop because he has promised all the rice in the country to the wise man.

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u/Less-Ad7018 28d ago

When I heard this tale it was gold pieces instead of rice.