Oh great, so those seemingly completely useless keys are in fact... completely useless.
NumLock, on the other hand, is not so useless. It lets the numeric pad (the right side of the keyboard) switch between numeric input or the ins/del/etcetera functions. Okay, so the entire numeric pad is redundant, but those keys do have different scancodes than their equivalents elsewhere on the keyboard, meaning that you can safely use 'em as hotkeys.
I've got NUM+ and NUM- mapped to volume up/down for instance, while NUM/ tells foobar to play a random track, etcetera.