Online Sudoku puzzles, which are ideal for use on an interactive white board, with...

• different size grids - 4x4, 6x6 and 9x9
• different levels of difficulty - easy, medium and hard

and with the options of using...

• numbers
• symbols or
• letters.

Ideal for all ages and all levels; develop strategies, interact, progress.

Have a go at http://www.jigsawdoku.com/.