Brenda Williams, the center’s director, said once the clock strikes six, every room in the center from the computer lab to the dancing studio to the basketball court is full. C.C. Jackson is one of the eight centers that have been operating on Saturdays, and Williams said it has made a marked difference to the community. Between 150 and 350 kids come through the doors on a given Saturday and play video games, experiment in the computer lab or take part in activities like football and dancing.