Mac OS Utilities
A classic 13 row Japanese Soroban with an optional digital display for practice.
Hold the Shift key while clicking on an Earth bead to also add the Heaven bead.
Added a menu page with a link to the standard soroban, a practice soroban with a digital display and a direct link to a great website for abacus instruction.
Also moved the reset button away from the abacus beads so it won't get clicked accidentally during calculations and shifted the digit markers over one bead.
Added soothing wind chimes to the opening menu to calm you before you attempt to learn the abacus. ;-P