A card trick anyone can do

YouTube link.

Mathematical card tricks are the best ones to learn, because no sleight-of-hand is required.  A hat tip to Mark Frauenfelder for creating this video to illustrate the methodology of a clever trick posted at Greg Ross' Futility Closet.

Math enthusiasts can calculate why the trick works; the rest of us can read the explanation by Noah Luck Easterly in the Boing Boing comment thread.