Though it's a simple puzzle to learn, there isn't an easy way to explain how it works. You really have to look at it. The goal is to fill out a grid of 81 boxes that are sectioned off into nine three-by-three squares. Each column and row must contain the numbers 1 through 9 and you can only use the same digit once in each row and column.
Now here's the rub: Each of the nine three-by-three boxes must also contain the numbers 1 through 9.
Our crossword puzzles are more challenging, but sudoku is definitely harder than Jumble and Word Sleuth. The puzzles are also rated from "easy" to "hard" - and the hard ones are hard, trust me.
Still, if you are looking for a unique brainteaser that will test your logic ability, then this puzzle is right up your alley.
Now to the reader call-in line: Starting this week, we will begin offering readers the option of using e-mail to submit comments to our daily Mail Call and You Said It columns, which appear in The Daily Mail and The Morning Herald, respectively.
You may simply type your comments and send them to email@example.com or firstname.lastname@example.org. Please be sure to include your hometown. Of course, you still may phone in your comments, which are transcribed daily by an editorial assistant in the newsroom. But if you want to e-mail your comments to us, then please do so.
We first began offering Mail Call in The Daily Mail about 10 years ago. Since we began offering the reader comment service in our morning paper (You Said It) last November, the number of calls has more than doubled. We now receive upwards of 75 or more calls on some days.
Such a high volume of calls means that we can't print every comment that we receive - just like we have to edit lengthy letters to the editor on our opinion pages.
Your comments stand a better chance of getting printed if you are expressing an opinion about a specific issue. Mean-spirited and personal attacks are edited out. So are comments that we determine are factually wrong. Some entertaining comments and jokes are left in as long as they aren't too stupid - though that point is debated weekly in the column by readers.
Both of these changes make our newspaper a little better. Some readers who don't work crossword puzzles have asked for a better variety of puzzles. Other readers have made repeated requests to be allowed to send in comments via e-mail, which makes sense in this day and age when most people use a computer at home or work.
We listened to your suggestions. I hope you like the improvements.
Terry Headlee is executive editor of The Herald-Mail. He may be reached at 301-733-5131, ext. 7594, or by e-mail at email@example.com.