## Plus Advent Calendar Door #4: Special Sudokus

Submitted by Marianne on December 3, 2010It's the weekend, the snow is gently falling outside, and inside the fire is blazing ... what better way to spend the time than puzzling over our special *Plus* sudokus? They're not what you're used to...

- Open a can of worms sudoku
- Sudoku round the clock
- Mystery sum sudoku
- Greater than sudoku
- The Duplex difference sudoku
*Plus*magazine sudoku

Or if you'd rather like to spend your time reading, find out about the history of sudoku, why sudoku puzzles help to take pictures of tiny things like cells, or muse on some sudoku questions that puzzle mathematicians.