- 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+ 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.
- 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.
- Dick's Math Puzzle Page - A collection of mathematical puzzles, some original, with fully worked solutions.
- 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 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, 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.
- A Primer on Cryptarithmetic - Instructions, examples, references and links.
- 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 Puzzling World of Barry R. Clarke - Brain teasers, articles and puzzles forum.
- 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.
XML-feeds
- Mathschallenge.net (RSS) - A website dedicated to the puzzling world of mathematics.
- Nick's Mathematical Puzzles (RSS) - A collection of puzzles, with hints, solutions, and links to related mathematical topics.
