The normal method of calculation in ancient Rome, as in Greece, was by moving counters on a smooth table.
ðə nˈoːɹməl mˈɛθəd ʌv kˌælkjʊlˈeɪʃən ɪn ˈeɪntʃənt ɹˈoʊm, æz ɪn ɡɹˈiːs, wʌz baɪ mˈuːvɪŋ kˈaʊntɚz ˌɔn ɐ smˈuːð tˈeɪbəl.