Recreations
- 63
- Mathschallenge.net
- A website dedicated to the puzzling world of mathematics, with a discussion forum.
- 65
- Missouri State University's Problem Corner
- Math problems in three levels of difficulty: high school, advanced, and challenge. With archives.
- 67
- Nick's Mathematical Puzzles
- A collection of puzzles, with hints, solutions, and links to related mathematical topics.
- 68
- Paul Hsieh's Puzzles
- Logical and mathematical brain teasers, with an indication of difficulty. Hints are provided; solutions are available by email.
- 69
- Puzzle of the Week Archives
- A collection of puzzles, with hints and full solutions. Compiled by George Moody.
- 71
- Sequence Puzzles and Problems
- Find the next entry in each sequence. With links to related sites. Compiled by Torsten Sillke.
- 72
- Storkey: Two Envelope Paradox
- A tough but simply defined problem which demonstrates key issues in probability.
- 75
- Wu's Riddles
- A collection of riddles, puzzles, and technical interview questions, with a discussion forum.
- 76
- A Very, Very Magic Square
- A 25x25 magic square with 25 sub-squares and other properties. Maple program and PostScript files available for download.
- 77
- All You Wanted to Know About Magic Squares
- Introduction to magic squares. Basic/C computer programs to generate odd squares. Calculates 8x8 squares with any given date on the first line.
- 78
- Finding Magic Squares Using CCM
- The Chemical Casting Model (CCM) generation method is demonstrated with a Java Applet. Source code and description of algorithm included. (English/Japanese) [JRE required for Applet only].