Charlie wanted to review the video on powers of ten. The video takes the viewer on a series of zoom-outs to show inceasing powers of ten against the backdrop of astronomical scale and then reverses the process to delve into the microscopic world. While watching the video, Charlie asked what a light year is and I helped him understand that it isn't a time. It is the distance light traves in one year. I then told him to work with the Math Lines online game to practice his subtraction skills. There was no assignment.