Today Andrew and I spent the first half of class in the art room to assist the teachers in a conference. Then we went back to his class and pulled some SAT problems. I gave him a problem similar to what we were working on yesterday: The coordinate Geometry of circles. He remembered what to do. Next, I gave him a problem where one of the centers was at zero. The equation looked different to him, so he had to determine when there are no visible numbers, it implies the coordinates are zero.