I have three nice sites related to tessellating. Maybe these are some you already have, if not, they are worth looking at. I have done tessellations with my 5th graders and they have done a very nice job. If any elementary person is intersted in the lesson plan, just let me know. If you can get your hands on The SRA Art Connections Level 5 text or teacher's manual on pages 80-83 there is an excellent explanation with samples on the tessellating process. Barbara