To help you through Christmas we have developed Zudoku

Zudoku is available for the following platforms:

• Windows 98, 2000, NT and XP
• Mac OSX 10.x
• Linux
• The ultimate PDA - Zaurus

Zudoku has different levels so can be played by anyone coming for Christmas.

Pick a difficult puzzle for the kids, print them off a copy each, then select the Solve option and print the solution off for yourself. It will keep them busy for hours and you don't even need to work it out!

All you need to do is register.

You can click here to log in and download the appropriate version of Zudoku for your computer