There are things that every Maker needs: a good hammer, a good workspace, a good joke…and of course one good card trick. You may not have the opportunity to demonstrate it often — all the better! But when you need it, you need it. Here, in case you don’t have it yet, is a truly awesome card trick.
Continue “folding” along any lines until you’ve restacked the cards into one pack of sixteen. Done right, twelve cards should be face down and four should be face-up (or vice versa). Of course, the trick seems destined to return the original four face-up cards. And that would be neat. But what’s even neater is that no matter how you fold the grid of sixteen, the four cards that face opposite the others are — wait for it … wait for it — the four aces!
WHY IT WORKS:
I had to do this trick three times to believe that it actually works. (It does.) The reason it works has to do with the properties of odd an even numbers. In this trick this odd/even thing means that if you flip a card an even number of times, it ends with its original up side facing up. If you flip it an odd number of times, the side that was down faces up. Now imagine arranging this trick’s sixteen cards in the pattern of a chessboard, as shown here.
However you “fold” a chessboard, all the white spaces undergo exactly one more or one fewer flip than the black spaces — one is odd and one is even — and so no matter how you fold chessboard-patterned cards, they will eventually turn into a pile of sixteen cards all facing the same way. Try it. But in this trick, you didn’t arrange the cards like a chessboard, did you? No. Exactly four cards in this trick’s setup differ from the chessboard pattern. And so these same four cards will point the wrong way in your folded stack.
Of course, these cards are the four aces.