## Saturday, December 27, 2008

### Sudoku: accuracy, accuracy, accuracy

Sudoku is a game to help fight flawed thinking.

A while ago I tried Sudoku and started at the hard puzzles but gave it up, having passed it off as a child's game. Mistake! How to play Sudoku? If you start at the easy puzzles and learn the skills first, the reward is that it's fun! It is important and useful to exercise your mind and make it more flexible. This is a game where you are rewarded for correcting your thinking and for being right!

Accuracy is most important in Sudoku, or else you must backtrack, erase and start again. (How would I know?)

To find a Sudoku game, try googling. Search for "easy sudoku" at Google Images to print out free puzzles. There are lots of inexpensive Sudoku books to buy at bookstores and grocery checkouts with graduated puzzles.

Here are some secret steps to successful Sudoku, the R(epeats)-L(ine)-B(ox) system (it's all a blur). These steps are interchangeable. It's easiest to start with the first, then the second and third, constantly going back and doing more of step one.

1. Repeats. With pencil, eraser and puzzle in hand, first check lines in the big box for repeated numbers and fill in the third line. If there is, say, a "seven" on the first and third line, and only one spot to fill in the middle box, then it's a "seven". You need to go around and check every line, left to right (or right to left), and top to bottom (or bottom to top).

2. Line. After you have finished filling in these numbers, see if you can finish an entire line since you might have only about 2-4 boxes to fill in, and a number cannot repeat. Again, you need to check every direction.

3. Box. You can finish any one of the nine boxes within the big box when you have just a few spots left blank, as each box cannot repeat a number inside of it.

Just keep going very carefully. To win, each move must be a defendable mathematical certainty. You should be able to finish it without needing to check the answer. If you're stuck, get an easier, winnable puzzle, one you can finish. Finally, you will have successfully finished a complete Sudoku puzzle. It's guaranteed to give you a feeling of accomplishment and achievement and it's fun! Finishing a puzzle perfectly is the goal. Increasing speed is even better.

Congratulations!

Hope you have fun playing. Happy Sudoku!

Special thanks to Amy Seymour.