Milésimas

Milésimas is the plural form of milésima, a fraction that denotes one thousandth part of a quantity. One milésima equals 1/1000 of a unit and, in decimal notation, 0.001. It is closely related to the percent (0.1% equals 1/1000) and to the per mille scale, where 1 milésimo corresponds to 1‰.

The term is used across mathematics, science, and engineering to express small parts or levels of precision. When measurements are described to a certain number of milésimas, the value is given to three decimal places in the reference unit. For example, 0.123 m can be read as 123 milésimas de metro. In time, 0.001 segundos is a milésima de segundo, commonly referred to as a millisecond in standard naming, though the phrase milésima de segundo may be used in everyday language.

Etymologically, milésima derives from Latin mille, thousand, with the feminine suffix -ésima, forming the fractional ordinal. The plural milésimas is used when referring to multiple thousandths.

In summary, milésimas express very small proportions of a unit, precisely one part in a thousand, and they play a role in contexts where precise subdivision of quantities is required.

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