Fun, great to view, some people have time on their hands!
These experiments were created by designers and programmers from around the world using the latest open standards, including HTML5, Canvas, SVG, and more. Their work is making the web faster, more fun, and more open - the same spirit in which we built Google Chrome.
The Maths Arcade section of this website has some really fun games for students from P-6. They can choose their level and select a game to practice their maths skills independent.
Interactive site on simple and compound machines (It lists "gears" as a simple machine, which is the only place where I have seen this, as everywhere else just has the traditional 6 simple machines. Likewise, some of the examples of various machines are a bit tenuous, but it is a fun site, nonetheless)
A good resource for all ages, contains examples/working out and also questions and problems for students to solve. Has a wide variety of topics and activities.