Fact
Rice on a chessboard bankrupts a kingdom
One grain on the first square, doubling each time. By square 64 you owe more rice than exists.
The total comes to 2 to the power of 64 minus 1 – about 18 quintillion grains, or many times current annual world rice production. The legend usually ends with the inventor being executed rather than paid. It remains the clearest illustration of why exponential growth defeats intuition.