THE ABACUS
In order to view the ABACUS you need the JAVA RUNTIME ENVIRONMENT (JRE) loaded on your computer. If you do not have this environment you may download it from http://java.sun.com/getjava/
On this electronic version of ABACUS you may drag the beads using your mouse cursor. The Rule of Abacus is : WHEN YOU HAVE TEN BEADS TO THE RIGHT ON A WIRE, THEY ARE REPLACED BY MOVING ONE BEAD TO THE RIGHT ON THE NEXT WIRE.