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.
The Stanford Mathematics Problem Book: With Hints and Solutions by G. Polya, J. Kilpatrick Based on Stanford University's well-known competitive exam, this excellent mathematics workbook offers students at both high school and college levels a complete set of problems, hints, and solutions. 1974 edition.