Etymology tree Proto-Indo-European *h₂er- Proto-Indo-European *-éh₁ti Proto-Indo-European *h₂reh₁- Proto-Indo-European *-éyti Proto-Indo-European *h₂rey-der. Ancient Greek ᾰ̓ρῐθμός (ărĭthmós) Proto-Indo-European *-eti Proto-Indo-European *-eyéti Proto-Indo-European *-esyéti Proto-Indo-European *-éh₁ti Proto-Indo-European *-yeti Proto-Indo-European *-éh₁yeti Proto-Indo-European *-yeti Proto-Indo-European *-éyeti Ancient Greek -έω (-éō) Ancient Greek ἀριθμέω (arithméō) Proto-Indo-European *-tis Proto-Hellenic *-tis Ancient Greek -τις (-tis) Ancient Greek -σῐς (-sĭs) Proto-Indo-European *-kos Proto-Hellenic *-kos Ancient Greek -κός (-kós) ? Proto-Indo-European *-tós Proto-Hellenic *-tós Ancient Greek -τος (-tos) ▲ Ancient Greek -κός (-kós) ? Ancient Greek -τικός (-tikós) Ancient Greek ἀριθμητῐκός (arithmētĭkós) Ancient Greek ἀριθμητῐκή (arithmētĭkḗ)bor. Latin arithmēticabor. ▲ Ancient Greek ἀριθμητῐκός (arithmētĭkós)bor. Latin arithmēticusbor. Old French arismetiquebor. Middle English arsmetike English arithmetic From Middle English arsmetike, from Old French arismetique, from Latin arithmētica, from Ancient Greek ἀριθμητική (τέχνη) (arithmētikḗ (tékhnē), “(art of) counting”), feminine of ἀριθμητικός (arithmētikós, “arithmetical”), from ἀριθμός (arithmós, “number, counting”), from Proto-Indo-European *h₂ri-dʰh₁-mó-s, form of *h₂rey- (“to count, reason”). Used in English since 13th century.

algorism • arithmetical • linear • number theory