KidzClix

KidsClix offers a number for fun activities, ranging from chess to sudoku to fun games & puzzles - And they update them every month, so you will not get bored. While a lot of the content can only be accessed if you get a subscription, you can 'try' the site out by clicking on the 'Free Issue' button on the top left. If you do end up subscribing for it, your school will thank you, for part of the subscription money will be donated to them!