15 Puzzle of Sam Lloyd: Play online Sam Lloyd's "15" puzzle. The funny story and mathematical implications of this game. Some funny logical problems with the 15 game.
A Primer on Cryptarithmetic: Instructions, examples, references and links.
A+ Math: Interactive math help for K-12 students with flashcards, Math Wordfind, Homework Helper and worksheets.
Aha! Puzzles: Puzzles, books, games and tests with designed by Lloyd King, author of "Test Your Creative Thinking".
AIMS Puzzle Corner: Provides over 100 puzzles with the goal of creating an engaging learning environment.
Algebraic Math Puzzles: A collection of puzzles at high school level. Does not include answers.
Alien Tiles: Object of puzzle is to try to get color pieces to create certain patterns in cube.
Alphametic Puzzles: Numerous puzzles, links, puzzle solver, and a generator.
Alphametics and Cryptarithms: Puzzles in which letters or symbols are substituted for the digits in an arithmetical operation like addition.
Alphametics Page: Compiled by Mike Keith. Examples of various genres.
Archive Creative puzzles: Interactive puzzle archive with descriptions for puzzle construction and a special childrens puzzle page.
Ben Robinson's Cross-Number Puzzles: A collection of cross-number puzzles: similar to crosswords, but using digits instead of letters. Many involve complex mathematical reasoning.
Brain Teasers and Maths Puzzles: Interactive logical and mathematical puzzles with feedback and detailed solutions.
Brain Teasers by QBrute: Original brain teasers with solutions.
Calculus-Help Problem of the Week Archive: Calculus based problems range from easy to difficult.
Clever Games for Clever People: Games that interest John Conway including Rim and Traffic Jam.
Colorful Mathematics: Educational software presents advanced mathematics to K-12 students in a game-oriented approach, using coloring and drawing techniques to illustrate concepts from graph theory and computer science.
Contest Center Cryptarithms: Examples of cryptarithms, with prize competitions for subscribers.
Downloadable and online games: A variety of Flash- and Java-based games and puzzles.
Free Puzzle Collections: Educational and recreational puzzles for teachers, students and parents. Each puzzle is graded by difficulty and has a hint. Solutions are available to members.
Group Games: Animations that develop the theory behind such puzzles as the Rubik cube.
Interactive Mathematics Miscellany and Puzzles: Java-based math resource including articles, puzzles and links.
Logic Puzzles: Collection of original numerical-logic puzzles. Many are long and difficult, involve sorting and comparing long lists and are intended to be solved using a good spreadsheet program.
Logicville: Educational puzzles, brain teasers, and word games such as anagrams, cryptograms, alphametics, doublets, tangrams.
Magic Math Kingdom: Learn math through games and quiz-oriented tutorial.
Math Forum: Resources, problems and forum for teachers and students in mathematics.
Math Puzzles: Logic puzzles and riddles with some solutions.
MatheMagic: A collection of mathematical puzzles, jokes and articles.
MatheMajik: Indian site featuring calculation tricks and math puzzles.
Mathematical Games: A collection of pencil and paper games with mathematical content. Many can be played through the site.
Mathematical Recreations: Detailed exploration of a selection of mathematical topics.
Mathproblems.info: Over one hundred and fifty math problems ranging from basic math to differential equations.
Mathpuzzle.com: Celebrates math puzzles and mathematical recreations.
Mathschallenge.net: A website dedicated to the puzzling world of mathematics and computer programming, with a discussion forum.
Mathwizz: Interactive math problems for abilities ranging from middle school to university.
Mixed Up Math: Logic problems, where equations are mixed up. In various formats like boxes, crosses, diagonals, mazes. Free download.
Mr Titen's More Than Math: Mathematics teacher provides puzzles for students.
Nandor's Exhaustive Chemical Words Pages: Lists all the English words, word squares, and magic squares that can be written using chemical symbols.
Nick's Mathematical Puzzles: A collection of puzzles, with hints, solutions, and links to related mathematical topics.
Paul Hsieh's Puzzles: Logical and mathematical brain teasers, with an indication of difficulty. Hints are provided; solutions are available by email.
Perfect Times: Teaches and assesses fluency of multiplication and division tables using online cards. Submit data and compare results.
Polyhedra Links: Pastime and activity links for various geometric patterns, polygons and polyhedra by Jill Britton.
Polymorf - Symmetry of Polyhedra: A demonstration of the symmetry and transformational properties of the Platonic and Archimedean solids.
Problem Solutions: Archive of problems and solutions, compiled by Dr Alec Mihailovs of Shepherd College.
Puzzle of the Week Archives: A collection of puzzles, with hints and full solutions. Compiled by George Moody.
Puzzles of Leonid Mochalov: A variety of challenging geometrical and arithmetical puzzles, many with solutions.
Pythabacus: Description and instruction of using the ancient Pythagorean Abacus to do arithmetic.
Scott Kim: Puzzles for web, computers, and print; ambigrams.
Sequence Puzzles and Problems: With links to related sites. Compiled by Torsten Sillke.
SMSU Problem Corner: Math challenges Southwest Missouri State University in three levels of difficulties.
Storkey: Two Envelope Paradox: A tough but simply defined problem which demonstrates key issues in probability.
The Contest Center: Classic puzzles and riddles requiring only simple logic and elementary math.
The Enigmatic World of Philip Carter: Collection of brain teasers from the author of IQ books.
The Little Math Puzzle: The Little Math Puzzle has been a K-12 Internet activity since 1995 for grades 5-9. Currently the puzzles have ceased but the site maintains complete archives of past problems.
The Null Set: Puzzles collected by Guy Kindler, most requiring some undergraduate mathematical knowledge. Some hints are provided.
The Puzzling World of Barry R. Clarke: Brain teasers, articles and puzzles forum.
Tile Tris: Tile a spheroid working room aperiodically or periodically. Includes free demo download.
Torus and Klein Bottle Games: Collection of Java-based educational puzzles.
Wu's Riddles: A collection of riddles, puzzles, and technical interview questions, with a discussion forum.