 Storkey: Two Envelope Paradox - http://www.anc.ed.ac.uk/~amos/doubleswap.html A tough but simply defined problem which demonstrates key issues in probability. |
 Alphametics Page - http://members.aol.com/s6sj7gt/mikealp.htm Compiled by Mike Keith. Examples of various genres. |
 MatheMajik - http://mathemajik.tripod.com/ Indian site featuring calculation tricks and math puzzles. |
 Ben Robinson's Cross-Number Puzzles - http://www.users.bigpond.com/bendr/xwd/numeric/index.html A collection of cross-number puzzles: similar to crosswords, but using digits instead of letters. Many involve complex mathematical reasoning. |
 Puzzle of the Week Archives - http://ecg.mit.edu/george/puzzles/ A collection of puzzles, with hints and full solutions. Compiled by George Moody. |
 Brain Teasers by QBrute - http://www.angelfire.com/empire/qbrute/ Original brain teasers with solutions. |
 Brain Teasers and Maths Puzzles - http://www.syvum.com/teasers/ Interactive logical and mathematical puzzles with feedback and detailed solutions. |
 Math Puzzles - http://www.math.utah.edu/~cherk/puzzles.html Logic puzzles and riddles with some solutions. |
 Algebraic Math Puzzles - http://www.lifesmith.com/mathpuz1.html A collection of puzzles at high school level. Does not include answers. |
 Scott Kim - http://www.scottkim.com/ Puzzles for web, computers, and print; ambigrams. |
 Mathpuzzle.com - http://www.mathpuzzle.com/ Celebrates math puzzles and mathematical recreations. |
 The Enigmatic World of Philip Carter - http://www.knowl.demon.co.uk/ Collection of brain teasers from the author of IQ books. |
 A+ Math - http://www.aplusmath.com/ Interactive math help for K-12 students with flashcards, Math Wordfind, Homework Helper and worksheets. |
 Group Games - http://www.dmi.units.it/~logar/duek2/index_engl.html Animations that develop the theory behind such puzzles as the Rubik cube. |
 The Little Math Puzzle - http://www.sprucelog.com/lmp/ 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. |
 Alien Tiles - http://www.alientiles.com/ Object of puzzle is to try to get color pieces to create certain patterns in cube. |
 Wu's Riddles - http://www.ocf.berkeley.edu/~wwu/riddles/intro.shtml A collection of riddles, puzzles, and technical interview questions, with a discussion forum. |
 Logicville - http://www.logicville.com/ Educational puzzles, brain teasers, and word games such as anagrams, cryptograms, alphametics, doublets, tangrams. |
 Free Puzzle Collections - http://www.freepuzzles.com/ Educational and recreational puzzles for teachers, students and parents. Each puzzle is graded by difficulty and has a hint. Solutions are available to members. |
 Nandor's Exhaustive Chemical Words Pages - http://www.wellington.org/nandor/chemwords/chemwords.htm Lists all the English words, word squares, and magic squares that can be written using chemical symbols. |
 Mathematical Games - http://www.madras.fife.sch.uk/maths/games/ A collection of pencil and paper games with mathematical content. Many can be played through the site. |
 The Puzzling World of Barry R. Clarke - http://barryispuzzled.com/ Brain teasers, articles and puzzles forum. |
 Paul Hsieh's Puzzles - http://www.azillionmonkeys.com/qed/puzzles.html Logical and mathematical brain teasers, with an indication of difficulty. Hints are provided; solutions are available by email. |
 Nick's Mathematical Puzzles - http://www.qbyte.org/puzzles/rss2.xml A collection of puzzles, with hints, solutions, and links to related mathematical topics. |
 Nick's Mathematical Puzzles - http://www.qbyte.org/puzzles/ A collection of puzzles, with hints, solutions, and links to related mathematical topics. |
 AIMS Puzzle Corner - http://www.aimsedu.org/puzzle/ Provides over 100 puzzles with the goal of creating an engaging learning environment. |
 Mathschallenge.net - http://mathschallenge.net/rss2.xml A website dedicated to the puzzling world of mathematics. |
 Mathschallenge.net - http://mathschallenge.net/ A website dedicated to the puzzling world of mathematics, with a discussion forum. |
 Calculus-Help Problem of the Week Archive - http://www.calculus-help.com/problem.html Calculus based problems range from easy to difficult. |
 Torus and Klein Bottle Games - http://www.geometrygames.org/TorusGames/index.html Collection of Java-based educational puzzles. |
 MatheMagic - http://geocities.com/mathimoh/ A collection of mathematical puzzles, jokes and articles. |
 A Primer on Cryptarithmetic - http://www.geocities.com/Athens/Agora/2160/primer.html Instructions, examples, references and links. |
 Logic Puzzles - http://www.geocities.com/bob_kraus_2000/ 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. |
 Mr Titen's More Than Math - http://www.geocities.com/EnchantedForest/Tower/1133/ Mathematics teacher provides puzzles for students. |
 Mathproblems.info - http://mathproblems.info/ Over one hundred and fifty math problems ranging from basic math to differential equations. |
 Mixed Up Math - http://www.kprobe.com/kprobe/mu.htm Logic problems, where equations are mixed up. In various formats like boxes, crosses, diagonals, mazes. Free download. |
 Pythabacus - http://www.pythabacus.com/ Description and instruction of using the ancient Pythagorean Abacus to do arithmetic. |
 Aha! Puzzles - http://www.ahapuzzles.com Puzzles, books, games and tests with designed by Lloyd King, author of "Test Your Creative Thinking". |
 Mathwizz - http://www.mathwizz.com/ Interactive math problems for abilities ranging from middle school to university. |
 Magic Math Kingdom - http://www.nes-lab.com/english2/ Learn math through games and quiz-oriented tutorial. |
 Colorful Mathematics - http://www.math.ucalgary.ca/~laf/colorful/colorful.html 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. |
 Alphametic Puzzles - http://www.tkcs-collins.com/truman/alphamet/ Numerous puzzles, links, puzzle solver, and a generator. |
 Mathematical Recreations - http://www.mathrec.org/ Detailed exploration of a selection of mathematical topics. |
 Interactive Mathematics Miscellany and Puzzles - http://www.cut-the-knot.org/ Java-based math resource including articles, puzzles and links. |
 Polymorf - Symmetry of Polyhedra - http://www.polymorf.net/ A demonstration of the symmetry and transformational properties of the Platonic and Archimedean solids. |
 15 Puzzle of Sam Lloyd - http://www.holotronix.com/samlloyd15.php Play online Sam Lloyd's "15" puzzle. The funny story and mathematical implications of this game. Some funny logical problems with the 15 game. |
 Contest Center Cryptarithms - http://www.contestcen.com/rithms.htm Examples of cryptarithms, with prize competitions for subscribers. |
 The Contest Center - http://www.contestcen.com/classic.htm Classic puzzles and riddles requiring only simple logic and elementary math. |
 Dick's Math Puzzle Page - http://www.mod2.org/ A collection of mathematical puzzles, some original, with fully worked solutions. |
 Creative puzzles - http://www.creatievepuzzels.com/ Interactive puzzle archive with descriptions for puzzle construction and a special children's puzzle page. |
 Downloadable and online games - http://www.gameintellect.com/ A variety of Flash- and Java-based games and puzzles. |
 Perfect Times - http://www.perfect-times.co.uk/ Teaches and assesses fluency of multiplication and division tables using online cards. Submit data and compare results. |
 Polyhedra Links - http://britton.disted.camosun.bc.ca/jbpolyhedra.htm Pastime and activity links for various geometric patterns, polygons and polyhedra by Jill Britton. |
 Puzzles of Leonid Mochalov - http://puzzlemochalov.com/ A variety of challenging geometrical and arithmetical puzzles, many with solutions. |