Virtual Abacus Tool

How to use the Soroban (Japanese Abacus)

This abacus (a Soroban) is used to represent numbers and perform calculations. Each rod represents a place value (ones, tens, hundreds, etc.), with the rightmost rod being the ones place.

• The Bar: Each rod is divided by a horizontal bar (the "reckoning bar").
• Heaven Bead (Top): The single bead above the bar has a value of 5 when moved *down* to the bar.
• Earth Beads (Bottom): The four beads below the bar each have a value of 1 when moved *up* to the bar.
• Reading a Rod: The value of a rod is the sum of the active beads (those moved towards the bar).
  • 0: Heaven bead is up, all earth beads are down.
  • 3: Heaven bead is up, 3 earth beads are up.
  • 5: Heaven bead is down, all earth beads are down.
  • 7: Heaven bead is down, 2 earth beads are up (5 + 1 + 1).
  • 9: Heaven bead is down, 4 earth beads are up (5 + 1 + 1 + 1 + 1).

To Use: Click any bead to move it (and any beads between it and the bar) towards the bar to "activate" it. Click it again to move it away. The total value is displayed at the top.