e-olio

We left off last time finishing all the horizontal and vertical gimmies in the puzzle. These are the numbers that it takes little effort to find. Remember the technique (check rows and columns of containers for duplicates and then see if the remaining container has a unique position for the number in question) as you will use it throughout the puzzle solution. Every number you put into the puzzle should trigger another gimmie search  in both the horizontal and vertical directions for the container in question.

OK, now where to we go? [Read more…]

This is the second in a series about the Sudoku puzzle and some of the solution methods. In the last post the puzzle was defined and the rules for solving were shown. In summary, you have a 9×9 array of squares that have to be filled with numbers such that each row, column and container contain one through nine with no repeats.

In this post we’ll show the method to find the “gimmies,” or numbers that you don’t really have to think very much about. Let’s recall the puzzle…

Recall the container rule that every container must have the numbers one through nine in it. Given that, consider the top three containers which form a group of three rows. Look for two of those containers having the same number in them. Sometimes this combination will define a unique place for that number in the third container. Let’s see an example of where that happens in this puzzle… [Read more…]

Sudoku? Why Sudoku and what is Sudoku? (By the way, it’s pronounced “Sue doh’ coo”.)

Sudoku is mostly seen as a number puzzle in newspapers. It’s basically a logic puzzle and has nothing to do with math. That’s important to understand as I’ve asked many people if they solve Sudoku puzzles and the almost universal answer when they say “no” is because they are not good in math.

It has nothing to do with math! [Read more…]