Someone who specializes in arithmetic.

Roget 85: numeration; numbering etc. v.; pagination; tale, recension^†, enumeration, summation, reckoning, computation, supputation^†; calculation, calculus; algorithm, algorism^†, rhabdology^†, dactylonomy^†; measurement etc. 466; statistics.    arithmetic, analysis, algebra, geometry, analytical geometry, fluxions^†; differential calculus, integral calculus, infinitesimal calculus; calculus of differences.    [Statistics] dead reckoning, muster, poll, census, capitation, roll call, recapitulation; account etc. (list) 86.    [Operations] notation, , addition, subtraction, multiplication, division, rule of three, practice, equations, extraction of roots, reduction, involution, evolution, estimation, approximation, interpolation, differentiation, integration.    [Instruments] abacus, logometer^†, slide rule, slipstick [Coll.], tallies, Napier's bones, calculating machine, difference engine, suan-pan^†; adding machine; cash register; electronic calculator, calculator, computer; [people who calculate] arithmetician, calculator, abacist^†, algebraist, mathematician; statistician, geometer; programmer; accountant, auditor.    ... show more

Dutch: rekenkundige
Polish: arytmetyk