This exercise enables students to measure the rate of rotation of the sun at various latitudes using an archive of 368 images of the sun obtained over a four month span in 2002 obtained by the GONG project. The program provided enables students to access the GONG images, display them as still images or animations, measure and record the positions of sunspots, plot its heliocentric coordinates versus time, and thus determine the apparent rotation period of the spot.