A Mystifying Mathematical Card Effect!
This trick first appeared in Card Colm: Low Down Triple Dealing.
Watch the “How To” Video:
This trick can also be found in the book, Mathematical Card Magic: Fifty-Two New Effects, by Colm Mulcahy, with a foreword by Max Maven. (A.K. Peters/CRC Press, 380 pp., 128 illustrations, August, 2013)