Archamendes and Math In The Sand Box

It is believed that Archamendes wrote in the sand before he wrote on paper (papyrus). I've even read that Archamendes carried with him a box of sand at all times offering him the ability to work on mathematics from anywhere. I believe there is merit in this method. I would encourage you to take your students outside before the school year is over, to the nearest sandbox (or my case, mud) and conduct class with a stick.