Here is an example of a 10 year old Surrey student that learned Google SketchUp during the summer and created the attached drawing.
dream house.skpdream_house.png The geometry lessons that are included in this activity are endless. You can create the 3-D shapes and manipulate them in a 3-D space.
What lessons might you use this for ?

Google SketchUp is currently educationally approved and waiting for technical approval.

This was done 5 years ago with Grade 7 students. While not very technical, the grade 7's enjoyed working with the shapes and being creative at the same time.