Quink by Phil Goldstein from Royal Magic (M10)

If you're looking for an offbeat close-up routine, you've found it!

The magician displays four cards, numbered 1, 2, 3, and 4. While the performer's back is turned, the cards are mixed and then sorted out by the spectator. The result is that some of the card are face up, and some are face down. The participant adds together either set of numbers to produce a random total. In a surprising climax, the performer reveals that this was known in advance, and the prediction was right in front of the audience from the very start!

Complete with special cards. No sleight of hand, and no gimmicks. Produced by Ton Onosaka's Magic Land of Japan.