Virtual Chinese Abacus
If a picture is worth a thousands words, then this "interactive" picture is priceless. Here, you can test drive a traditional Chinese abacus and learn how it works.
Use your mouse to move beads to and from the center bar. The result is automatically calculated and the results returned at the bottom right.
Place your cursor in the "Add/Substract" box, then type in a positive or negative number. That amount is calculated when you press "enter" or "return".
Press the "Reset" button to clear the abacus and start new.