Ivars Peterson, written about last week here, has announced his departure from Science News and Math Trek Blog for a position as Director of Publications for Journals and Communications at the Mathematical Association of America (MAA). His new blog, due in March 2007, will be called: **The Mathematical Tourist**.

Within the MAA Online website, Ed Pegg, back in September 2005, surveyed the varieties of Sudoku and showed many actual variants, some of which are regularly published (especially in Japan). It is an excellent article and a testament to Sudoku puzzlers’ low tolerance for boredom.

I especially like the Cubic Sudoku, which contains 2×4 rectangles on the cube faces with 1×8 “bent in the middle” strips that comprise the “rows” and “columns”. I’m an easy mark for 3-D puzzles.

On a Dutch Web site called Sudokube that I roughly translated with the help of babelfish, there is a hybrid of Sudoku and Rubik’s Cube available for sale for only 7.49 Euros per. (It offers a reduction in price to 5 Euros on its home page.)

This is what I find ironic: the original Rubik’s Cube consisted of 6 colors that get ultimately arranged to have one color per face of the cube. Sudokube has produced a rubik’s-like cube with the digits 1 through 9, in order, on each face, when solved.

Whereas, in my Sudoku Coloring Boards Cartoon of February 10, 2007, I rendered a Sudoku puzzle into a color mapping and a pattern mapping of the digits 1 through 9 from the original starting numbers. I’ve not seen any instances of this variant anywhere else.

I believe this will be very attractive to people whose visual color sense is advanced and whose number sense has been stifled in early life or atrophied. Since I teach math and feel rather un-visual, does anyone else concur (or not) with this?

How do you go about solving the Sudoku Coloring Puzzle as shown in the Cartoon? It seems to me that using small colored dots to make temporary notes in the boxes is analogous to the small numbers one writes as permissible entries. Do you solve the puzzle quicker or slower than one with numbers?

Obviously, solving this is perfect for the **Power Sudoku² white board** and colored markers found elsewhere on erasablegames.com. If you lack 9 different solid color markers, you can assign patterns for the missing solid colors instead, although that makes small notes harder to write.

The Puzzle is reproduced here and downloadable as a pdf file: