How many cards does a standard deck contain? 52 (plus two jokers).
How many cards do many games use? Because of the above, it's very often a multiple of 52 or 54.
How many blank cards do you need in many magic tricks? 52 - many humans can tell something is not quite right when they're holding 50 cards rather than 52.
How many cards does this have? 50.
How many stars does it deserve because of that? One.