December 2007

*Plus* magazine sudoku

This is the last puzzle in our series of sudoku variations. It was kindly provided by Brainfreeze puzzles, a puzzle making company run by the mathematician Laura Taalman and the software developer Philip Riley, whose book Color Sudoku is published by Sterling Publishing.

Each row, column, and jigsaw region must include exactly the letters you find in the words "Plus magazine", including repetitions. This means that each row, column, and region will contain the letter "a" *twice*.

If you are stumped by last issue's puzzle, here is the solution.

For some challenging mathematical puzzles, see the NRICH puzzles from this month or last month.