The Russian ruble was the first modern currency to use a decimal relationship, with 100 kopeks equal to one ruble, introduced during Peter the Great’s monetary reforms in 1704.
Earlier monetary systems often used awkward fractions inherited from medieval accounting. Russia’s reform connected the ruble to a silver coin standard and made its subdivisions easier to calculate for taxation, trade, and government accounting.
The word ruble is much older than the decimal system. It probably relates to a Russian verb meaning “to cut,” reflecting an earlier practice of cutting pieces from silver bars. The kopek, the ruble’s hundredth, takes its name from the spear-bearing image of Saint George on early coins.
The ruble should not be confused with the Belarusian ruble or historical currencies such as the Soviet ruble. Those currencies share the name but belong to different political and monetary systems.