Cyrillic numerals are a numeral system derived from the Cyrillic script, developed in the First Bulgarian Empire in the late 10th century. It was used in the First Bulgarian Empire and by South and EastSlavic peoples.[1] The system was used in Russia as late as the early 18th century, when Peter the Great replaced it with Hindu-Arabic numerals as part of his civil script reform initiative.[2][3] Cyrillic numbers played a role in Peter the Great's currency reform plans, too, with silver wire kopecks issued after 1696 and mechanically minted coins issued between 1700 and 1722 inscribed with the date using Cyrillic numerals.[4] By 1725, Russian Imperial coins had transitioned to Arabic numerals.[5] The Cyrillic numerals may still be found in books written in the Church Slavonic language.[6]