Sudoku Variation

My mother sent this sudoku variaton my way. She is a total puzzle junky and found this in the International Herald Tribune. All the normal sudoku rules apply, but you also have to fill the shaded areas with 1 through 9. Thanks, Mom!

May Issue of Wired

I really enjoyed the new issue of Wired. It's put together by guest editor, J.J. Abrams, who I'm ashamed to say I've never heard of, but whose issue as an homage to puzzling. He comes at it from various angles from a feature story of an artist who has been able to stump the best cryptographic minds in the world to an "enigmatrix" of the network connections between math, board games, plot, mysteries, magic code, and game theory. Best of all, it is full of puzzles. Enjoy the one above!

My New Favorite Puzzle: Tentaizu

I found a new puzzle. New to me anyway. It's called Tentaizu. I found it in the in-flight magazine on the way home from vacation. Btw, Southwest's magazine has the best puzzle section that I've ever seen. Not a reason to buy a ticket, but a definite perk. Anyway, I was completely charmed by this game. I thought we would play one this week. Maybe if we get excited we can try to automate a solution technique. I also tried to find a website that generates these like those I've found for Sudoku and KenKen. No luck.

Here are the instructions from Southwest's magazine:
In each of the grids on this page, stars are
hiding in 10 of the 49 squares. Your task is
to determine the positions of the stars. The
numbers in the grid provide clues: A number
in a square indicates how many stars lie next
to the square—in other words, how many
adjacent squares (including diagonally adjacent
squares) contain stars. No square with
a number in it contains a star, but a star may
appear in a square with no adjacent numbers.

What Would a Spectator Friendly Math Competition Look Like?

John and Steve have given me the challenge of creating a math competition that is actually fun to watch. There are tons of competitions out there. Rob runs one every year at Tunxis. However, almost all of these involve students sitting at a desk solving problems. What would a spectator friendly math competition look like? I have been thinking in two directions on this.

1) Taking math problems and making them physical. Classic bucket problems could be fun to watch if you took away paper and pencil and gave competitors actual buckets. (Think Die Hard with a Vengeance minus the bomb.) Or, here's a pack of M&M's, add these two numbers in base 6. Compass and protractor constructions would be interesting, particularly because hardly anyone knows how to do them anymore.

2) Structure the competition so that the audience can evaluate or judge the participants. Math contests are usually only judged for correctness and speed by experts. John mentioned the example of the poetry slam. How could this happen for math? Here are some ideas to get started with. Contestants solve a problem at home before the contest, come to the contest, and explain their solutions in 3 minutes or less. Then the audience judges them on the clarity/creativity of their explanations. Or, contestants prepare a 3 minute lecture/demonstration about math and the audience judges. Another wilder idea is to have them perform a creative task that doesn't have a correct answer. I use an enrichment activity in Math for Liberal Arts that might work. I have students create a poem using the power set structure on a set of words. The audience would definitely be able to evaluate this.

I'm not sure exactly what John and Steve had in mind for the bigger picture. I think they plan to have contests like this in all disciplines. They definitely gave me an interesting thought problem though.

Geek of the Week: Lee Bradley

Welcoming the newest member to our math community Lee Bradely. Lee has just been hired on as a full time math tutor in the Academic Support Center. He gave me a great problem. You have to create 5 rectangles, such that the length of each side of one of the rectangles is an integer 1-10. You have to use all 10 numbers, so no sides of the same length. Furthermore, the resulting rectangles have to tile together to form a square. He has sworn there are 4 solutions and has given me one. Stop over in the ACS to say hello and get a hint from him. Also check out Lee's website. He uses mathematics to make beautiful puzzles.

KenKen

Christina sent me a link about a cool new puzzle called KenKen. It is Sudoku-like, but involves arithmetic as well. Here is board. This is my understanding of the rules. A four by four board can be covered in the numbers 1 through 4 with no more than 1 of each being each row or column (like Sudoku). However, the board is divided into subregions or rectangular boxes. Take the first two boxes in row 1. That is a subregion. The two and division sign say that only the two numbers that occupy the box have to have a quotient of two. So you could fill in 4,2 or 2,1 for the first two boxes. Interesting, huh. And for teachers this could be a fun puzzle to work with classes. (In fact it was invented by a Japanese teacher.) The Times even has a lesson plan for you, or play just for fun online. Thanks Christina!