"I bought this for my 1st graders to make. Those that understood the weaving idea helped those that didn't quite have it. However, when I went around to glue the green ends, some were too short to glue to the outer edge. Appartently, the little guys had stretched the outer side frame. No matter how hard I tried to correct it, the mat had an eliptical shape. I don't think the children even noticed it, but unfortunately I did. If the green strips had been about 1/2 inch longer, it would have made the problem easier to adjust."