Friday, September 26, 2008

Friday Fun - Mini-Sudoku Puzzle (nine squares!)

For all of those that are tired of having to fill in a full Sudoku grid, here's a Mini-Sudoku Puzzle. The goal is to fill the nine squares with just the digits 1 to 9. The only hints provided are the "L-block" hints at each corner. Each value tells you the sum of the five squares that make up the two adjacent edges.

Note: This is not a magic square. You cannot make any assumptions about the totals of the rows, columns or diagonals.

See how quickly you can come up with the unique solution. I'll probably post the answer next Friday. In the meantime, please don't reveal the answer so others can enjoy the puzzle too. Post comments on whether you find this puzzle easy, hard, fun or frustrating. I'd be interested in your solving techniques and times, too.


  1. Thanks for this! My husband and I went about it in different ways. He reduced formulas and came up with a set of rules from which to work. I came up with the combinations of 5 digits to get the sums, and compared overlapping numbers to formulate the rules. We both finished with a mini-trial-and-error at the end.

    Love your blog!

  2. A spreadsheet works well, but care must be taken as to how it is set up.

  3. I tried trial and error first, but quickly realized my formulas for such would take too much time to solve, so I figured it out using a different formula which got it solved in a matter of seconds.


For NPR puzzle posts, don't post the answer or any hints that could lead to the answer before the deadline (usually Thursday at 3pm ET). If you know the answer, submit it to NPR, but don't give it away here.

You may provide indirect hints to the answer to show you know it, but make sure they don't assist with solving. You can openly discuss your hints and the answer after the deadline. Thank you.