Sunday, August 21, 2011

Prove intuitively that X * Y == Y * X

I needed an intuitive way to show this to my nephew (why is 6* 7 same as 7 * 6). Its really simple.

By definition of multiplication (Y * X) is read as "Y Xs are" which literally means X items stacked Y number of times. i.e. :

But notice that if we view this data horizontally it is Y items stacked X times i.e. X * Y!

therefore X * Y == Y * X