One of the most popular posts on this blog is the one on online whiteboards which I keep updated. Note with Screenr now retired as you will see in the updated post, Screencastomatic will allow you to achieve the same result as seen here – easily create a screencast and upload to YouTube.
This was part of some feedback on a homework task (Tethered Goat – see nrich version here).
The video has been uploaded to our class wiki (I use Wikispaces).
The wiki page includes advice on the features of a great solution, some questions for reflection and some images of student work.
John Page describes his ‘Math Open Reference‘ project as a free interactive textbook on the web, initially covering Geometry.
The tools include various function explorers. Younger students could explore linear functions for example, whilst older students could use the general Graphical Function Explorer to explore any functions, trigonometric for example.