This abacus allows the position of the beads to be fixed. It can be used by people with visual impairments.

3D models of frames that can hold 3, 5, 9, and 13 digits are available. Please print and assemble the required number of bead models to the selected frame.

The shaft that fixes the beads to the frame is not included in the 3D model. Please use commercially available metal or plastic round rods of 2mm diameter cut to the required length.