An Instrument For Performing Calculations.
Calculations Performed By Sliding Counters Along Rods.
Its Primary Purpose Is To Teach Arithmetic To Children.
One Colour Unit.
100 Beads. more details
An Instrument For Performing Calculations.
Calculations Performed By Sliding Counters Along Rods.
Its Primary Purpose Is To Teach Arithmetic To Children.
One Colour Unit.
100 Beads.