Cut the dowels into four-inch pieces. An average household abacus has eight rods but you can use as many as you want. Glue several craft sticks together to make abacus frame. Make the frame long enough to fit all of the dowel pieces with enough space between each rod for the bead to slide.
Line up the rods equal distances apart on the craft stick and mark the location of each with a pencil. Make a small line of glue on the pencil mark then glue the dowels in place. Let dry.
Put two beads on each dowel and push them to the frame. Place another length of craft sticks below the beads about 3/4 inch away from the top frame. Glue in place. This divides the two sections of the abacus. Let dry.
Thread five beads on the dowels. Place a third craft stick at the end of the dowels and glue in place. This is the bottom part of the abacus frame.
Glue three more craft sticks to the back of the other craft sticks to cover the glued rods and secure the beads in place.
Repeat Step 5 to thicken the back frame of the abacus and lift it off the table. Turn the abacus over and begin doing math.