It also meant a pebble used for calculating, or a small stone used as a counter in an abacus (Latin abacus , Greek abax ).

Abacus or abaco refers to calculations, especially the subject of direct calculations, using Hindu numerals without the help of the abacus (an instrument for calculating).

Stable rows made up of ten molecules act as the railings of the abacus.

I was going to say holding my first abacus, but actually holding what my father would consider an ample substitute to an iPad.

Abacus school is a term applied to any Italian school or tutorial after the 13th century, whose commerce directed curriculum placed special emphasis on mathematics, such as algebra, among other subjects.