If you read this blog regularly, you know that a lot of the things I make involve circles. My fascination with circles and radial symmetry has extended to kaleidoscopes, fibonacci spirals, music, card tricks, spinning wheels of lunch, and so on.
You may also know that I am prone to develop short term [...]

When I made 4,800 kakuro puzzles for this website, it never occurred to me that some of you would run out. But apparently, it’s happened, or at least that’s what the emails tell me.
So here’s 1,600 more.
Big ones too.
Enjoy :)

Barbara Katz sent me this link to a whiteboard that has been preprinted with a Sudoku grid, suitable for solving the puzzles here on my site.
Coooooool….

333 Great books for kids is one of a dozen new interactive mosaics I’ve added to my coverpop website. You can find the others by noodling around on the menus on the right, after you go there. More books, more DVDs, more clothes & accessories.
All the amazon-powered mosaics on the site are [...]

You asked for ‘em, you got ‘em. In addition to my new collection of 3,200 Jigoku puzzles, I have added 4,800 Kakuro puzzles and 1,600 Krypto Kakuro puzzles to my collection of free printable e-books.
For those of you new to Kakuro puzzles, I have also added an excerpt from my book, Masters Kakuro, which [...]

I’m making some new varieties of Sudoku puzzles which will be added to the puzzle pages soon.
Here is a preview of my new Jigoku (also known as Comparison or “Greater Than”) Sudoku puzzles:

Challenging
Tough
Super Tough
Insane

I call these Jigoku because of their resemblence to Jigsaw puzzles. Jigoku also means hell in Japanese, and you will indeed [...]

The majority of folks visiting this website for puzzles prefer the easy and intermediate puzzles. However, there is a small but vocal contingent campaigning for hard puzzles. Yes, even harder than my “super toughs”. So, I’ve added a 6th difficulty level, insane, which includes the puzzles that I omit from the [...]

Registration is now open for the Google US Puzzle Championship, organized by Nick Baxter and Will Shortz. Players have 2 1/2 hours to complete 25 fiendishly difficult puzzles.

The QFold puzzle website contains puzzles that are meant to be printed and solved with a pencil.
The puzzles are beautiful symmetrical designs that contain 20 hidden asymmetrical elements. To solve the puzzle, you identify these 20 elements of the puzzle and count the number of instances of each class of asymmetry (this [...]

Ed Pegg Jr, of the excellent MathPuzzle.com, has put up a complete set of scans of a profusely illustrated classic from 1914 containing 5000 unique puzzles.
Sam Loyd’s Cyclopedia of Puzzles.
If the name Sam Loyd isn’t familiar to you, perhaps it should be. Loyd was the inventor of the sliding 15-tile puzzle. Here’s [...]