CIEn

Cien is the Spanish cardinal number representing 100. It derives from Latin centum. As a determiner, cien denotes exactly one hundred when placed before a noun, as in cien libros. When counting beyond one hundred, Spanish uses ciento for 101 through 199 (ciento uno, ciento cincuenta). For 200 to 900, the hundreds take the forms doscientos, trescientos, cuatrocientos, quinientos, seiscientos, setecientos, ochocientos, novecientos. The thousands and larger scales use mil and million; for example, mil is 1,000, cien mil is 100,000, un millón is 1,000,000. The sequence of hundreds and thousands continues similarly.

Cien also appears in fixed expressions such as cien por ciento (one hundred percent) and cien veces (a hundred times). In decimal notation, cien is the base-ten hundred and is used as a round figure or in percentages and statistics.

In orthography, cien remains lowercase when used within a sentence, and it is not capitalized unless it begins a sentence or is part of a proper name or title.