The Ancient Romans developed the Roman hand abacus, a portable, but less capable, base-10 version of earlier abacuses like those that were used by the Greeks and Babylonians.[1]
^Sugden, Keith F. (Fall 1981). "A History of the Abacus". Accounting Historians Journal. 8 (2): 1–22. doi:10.2308/0148-4184.8.2.1.{{cite journal}}: CS1 maint: date and year (link)