The beauty of math and numbers and formulas and equations and so forth is that they can work without you ever understanding how the hell they work. What seems like complete randomness is actually just a math problem! Like this slick trick with a deck of cards. Take twenty or so cards and flip over five cards face side up and randomly insert them back into the rest of the deck. Shuffle it up all you want, split the deck in two and you can get the same exact amount of face up cards in each card pile.

How does it work? The trick is in the flip. Or the magic of math! Or sorcery of numbers solutions. [Quirkology]