Kadon has been creating, developing and making mathematically based mind games and puzzles since 1979. Our website contains a wealth of challenging activities you can play here for free or download to print out to work on. We also have the Internet's largest repertoire of combinatorial puzzles and games you can purchase right from the source. Those illustrated in the left margin are particularly recommended for home educators. Here is the motherlode of tools for building thinking skills that will prepare young people for a lifetime of creative and problem-solving success.
The links below will open in a new window. Simply close the window when you're done. Enjoy! And please let us know how useful any of these are for your homeschooling programs. Email us with Feedback.
Our featured attractions
- Puzzle Parlor
Solve samplers of 12 of our standard gamepuzzles, each with 3 levels of challenge. Many solutions exist for each. How many can you find? You need Flash for these.
These puzzlers are all still open, with new ones added occasionally. You could win a prize or at least get your name on the solvers' list. Some are extremely tricky.
- Memory Games
Match up pairs of imagesif you can remember where they are! Try your hand and memory on 18 different styles and improve your score with each attempt. A few have hidden links. Part of the fun is trying to find them.
- Children's Stories
Including an interactive adventure visiting other planets. Can you help Carl get back to earth in time for dinner?
- Coloring Book
A metagraphic design of art that you paint your way. Save your designs for future reference or to share with others.
Paper and pencil games
You may print out any of these pages for your personal use. Please contact us for permission beforehand if you'd like to republish them elsewhere.
Those marked with * are by others that you'll find on their sites. We share them here because they're great fun and kin to our own material. Please let us know if any links no longer work.
Some of these games may require your browser to have Java enabled. For Microsoft Internet Explorer, click Tools > Internet Options > Advanced, then scroll down to 'JIT Enabled' and check the check-box. If you still get a blank, download the latest Java plug-in.
Come up with new solutions and you may win a prize.
- Arc Anglesform one closed matched loop of all 25 tiles, with the minimum enclosed area.
- Big-Game Huntfind the mistakes.
- Chasing Squares the Maximum-Squares Challenge. Arrange the 16 tiles to form 24 or more "traceable" squares. Get 25 or more and win a prize.
- Cornucopiaform progressively longer rectangles with a 17-piece subset of Sextillions in 15 steps. New solutions win fame and a small prize.
- The Mini-Quiz serieswe've published 8 so far, all still open. No one has fully solved Quiz No. 6. We are curious and curiouser...
- Poly-5 Perimeterfill the border with a maximum of pentominoes. Improve on our results and win a prize.
- Rhombiominoesconnect all pieces of same color; new solutions win prize.
- Ten-Yen Enclosuresurround one color with the other two, in the smallest and the longest perimeter. New solutions win fame.
- Triangule-8 Sproutsform 25 sprouts or prove that 24 is the maximum possible.
- Vee-21, the Three-Color Problemthe search for more solutions of maximum color separation.
- Vee-21, the 25-Holes Challenge fit thirteen Vee-21 tiles (V-trominoes) rigidly into their 8x8 tray with no slipping or sliding. New solution wins a silver dollar (up to 25 winners). The 37 and 40 holes are also still unsolved and will win a prize.
Annotated links to other good sites for educational games, puzzles, and ideas.