I did not use this resource with any of my classes, though I really liked it and thought it would be useful. The reason I didn't use it was because I used another of the cre8ate resources (the one about representing 3D shapes in 2D) and, well, it just didn't work. There was too much to think about for the children. I think I didn't lead into it carefully enough. I should have been straightforward, but the codes were just too difficult. Maybe it would work better with a high set?