How is This Card Trick Possible?????

How is This Card Trick Possible?????

Self-working card tricks are automatic. They just work. However, that doesn’t mean they don’t fool you. This card trick is really mysterious and no one really understands the math behind it. Some will guess sleight of hand is at play, but it’s not! Yesterday’s card trick gave us a total of 21, and the final card was a 5 (from a freely selected pile). Today’s card trick gives us a 21, and the final card is a 2 (from a freely selected pile). How is that possib