Exclusively on NYTimes.com, updated with 6 new puzzles daily.
This extraordinary new math-logic puzzle started appearing in the NYTimes about a month ago. Link here to start playing. I also placed a link in the sidebar so that you can play every day. It will take you a few minutes to catch on to the rules and then you will give up Sudoku, Kakuro, your daily crossword puzzle and Jumble! I just started playing and I'm hooked. Most importantly, it will reinforce and develop basic arithmetic skills for your students and/or children!
I also recommend that you read the Times article which introduced this new feature. The creator is a talented and unique math teacher. Here is some fascinating background from the article:
KenKen was invented in 2004 by the Japanese educator Tetsuya Miyamoto, who founded and teaches at the Miyamoto Math Classroom in Tokyo. Students attend his class on weekends to improve their math and thinking skills. Mr. Miyamoto said he believes in “the art of teaching without teaching.”
He provides the tools for students to learn at their own pace using their own trial-and-error methods. If these tools are engaging enough, he said, students are more motivated and learn better than they would through formal instruction.About 90 minutes of class time each week is set aside for solving puzzles, usually designed by Mr. Miyamoto. The most popular one has been KenKen.
NOTE: The Math Problem of the Day for Wed 3-4-09 was deleted because I deemed that the context was inappropriate for younger readers who may visit. I'm assuming this was an aberration and this feature will resume shortly.