Mathemagic

More than 60 new puzzles and stunts based on the properties of numbers. Easy techniques for multiplying large numbers mentally, identifying unknown numbers, determining the date of any day in any year, such entertainments as The Lost Digit, and Psychic Bridge. Over 30 pages of magic squares, triangles, cubes, more. 76 illustrations. About the AuthorRoyal Vale Heath was a New York City broker, American Magician and puzzle enthusiast. His love for serial numbers, magic squares and dice was widely known.