i spent a saturday without going anywhere - how uncommon! instead i've been doing maths in the afternoon with svenja. we were doing geometric sequences and series and the chess problem showed up:

the man who invented the game of chess was asked to name his reward. he asked for one grain of corn to be placed on the first square of his chessboard, two on the second, four on the third and so on until all 64 squares were covered. he then said he would like as many grains as the chessboard carried. how many grains of corn did he claim as his prize?

the question is very easy to solve (sum formula), and you end up with the answer: 2^64-1 (two to the power of sixty-four minus one) or 1.845x10^19. that's a hell of a lot:
18'446'744'073'709'551'615 grains.

but. i struggle with the way they asked the question. until all 64 squares were covered - due to space problems, that would not take too long. as many grains as the chessboard carried - the chessboard would never carry the amount requested... but it doesn't really surprise me. already in primary school people were buying 50 melons in one go in the maths book...