Why Roman Numerals Failed

Try multiplying XLVII by XXIX in Roman numerals. You essentially cannot — the system has no place value, no zero, and no efficient way to multiply. Roman numerals work for recording (etching "MDCCLXXVI" on a building) but fail badly for calculation.

The switch to Hindu-Arabic numerals (0-9 with place value) is one of the most underrated revolutions in intellectual history. Fibonacci introduced them to Europe in Liber Abaci (1202), but resistance was fierce: Florence banned them from banking in 1299 because officials could not audit unfamiliar digits.