Primary Resources Number Board
This is an awesome way to visually demonstrate expanded notation. Click on/select parts of a big number to build it. This clearly shows kids how to say big numbers, such as 3,628: 3 thousand, 6 hundred, twenty, eight. It is easy to see what each digit represents. I wish you could type in number vs. clicking on it. I wish there was an audio component. Yet, I am still going to use this. It would be neat on an IWB, with the kids at their desks writing numbers on paper or small whiteboards! It does require Adobe ShockwaveFlash.