Abacus Simulator
Explore place value on a soroban with one upper bead and four lower beads per rod.
Represented value
Pink beads count toward the value. Click or tap a bead to move it toward or away from the middle bar. Nearby lower beads move together. Keyboard: use Tab to choose a bead, then Space or Enter to move it.
For 64 + 13: add one ten, then add three ones using +5 −2. The final value is 77.
The rightmost rod represents ones, then tens, hundreds, and so on. A lower bead counts as one unit of its column when moved toward the middle bar. The upper bead counts as five.
Try showing 7: move the upper bead and two lower beads toward the bar on the rightmost rod. To show 23, use two lower beads on the tens rod and three on the ones rod.