Lay a sheet of craft foam on a flat surface. Separate the legs of the compass so they are three-quarters of an inch apart. Place the pivoting point of the compass on the craft foam, no closer than 3 inches from the edge of the foam. Press the point into the foam to make a slight depression. Rest the pencil point of the compass on the foam. Scribe a circle on the foam. Remove the drawing compass.
Separate the legs of the compass so they are 2 1/2 inches apart. Replace the pivoting point of the compass in the depression on the foam. Rest the pencil point of the compass on the foam, then scribe a 5-inch circle. Remove the drawing compass.
Place the edge of a ruler so it extends from the center of the circle to the edge of the foam. Trace a line from the edge of the inner circle to the edge of the outer circle.
Cut out the outer circle with scissors. Cut on the radial pencil line that extends from the edge of the circle to its center. Trim and remove the inner circle, leaving a doughnut-shaped closet-rod divider. To install the divider, twist the ring apart at the radial cut. Place the inner circle over the closet rod, then twist the ring to close it.