Sorting those shapes

Last week, Carter did 3/4 the shapes in the shape sorter all by herself. We haven' really been working on that much yet, so I was pretty impressed. She seems to do it all by trial and error at this point, just trying them in one hole after another. When a shape fits in one hole, she gets very excited and then tends to try the next shape in the same hole. Oddly enough, she did all the circles, all the squares, all the stars and none of the triangles. She tried one triangle, got frustrated after a few holes and set it aside, then got tired of it with two pieces left--both of which were triangle. Kind of funny. But she seems to be making good progress on it.