abacus
n//əˈbakəs//abakus, kulram
(historical, obsolete) A table or tray scattered with sand which was used for calculating or drawing. [attested from c. 1387]
A device used for performing arithmetical calculations; (rare) a table on which loose counters are placed, or (more commonly) an instrument with beads sliding on rods, or counters in grooves, with one row of beads or counters representing units, the next tens, etc. [from late 17th c.]
(architecture) The uppermost portion of the capital of a column immediately under the architrave, in some cases a flat oblong or square slab, in others more decorated. [from mid 16th c.]