Please note that Mommsen uses the AUC chronology (Ab Urbe Condita), i.e. from the founding of the City of Rome. You can use this reference table to have the B.C. dates
From: The History of Rome, by Theodor Mommsen
Translated with the sanction of the author by William Purdie Dickson
The most definite evidence of the antiquity and original exclusive use of the decimal system among the Indo-Germans is furnished by the well-known agreement of all Indo-Germanic languages in respect to the numerals as far as a hundred inclusive.(2)
2. Cf. I. II. Indo-Germanic Culture
In the case of Italy the decimal system pervaded all the earliest arrangements: it may be sufficient to recall the number ten so usual in the case of witnesses, securities, envoys, and magistrates, the legal equivalence of one ox and ten sheep, the partition of the canton into ten curies and the pervading application generally of the decurial system, the -limitatio-, the tenth in offerings and in agriculture, decimation, and the praenomen -Decimus-.
Among the applications of this most ancient decimal system in the sphere of measuring and of writing, the remarkable Italian ciphers claim a primary place. When the Greeks and Italians separated, there were still evidently no conventional signs of number. On the other hand we find the three oldest and most indispensable numerals, one, five, and ten, represented by three signs--I, V or /\, X, manifestly imitations of the outstretched finger, and the open hand single and double--which were not derived either from the Greeks or the Phoenicians, but were common to the Romans, Sabellians, and Etruscans.
They were the first steps towards the formation of a national Italian writing, and at the same time evidences of the liveliness of that earlier inland intercourse among the Italians which preceded their transmarine commerce.(3) Which of the Italian stocks invented, and which of them borrowed, these signs, can of course no longer be ascertained. Other traces of the pure decimal system occur but sparingly in this field; among them are the -versus-, the Sabellian measure of surface of 100 square feet,(4) and the Roman year of 10 months.
3. Cf. I. XII. Inland Commerce of the Italians
4. Cf. I. II. Agriculture
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