1000th

1000th is the ordinal form of the cardinal number 1000, used to indicate position in a sequence. It denotes the element that follows the 999th item and precedes the 1001st. When written with digits, it appears as 1000th; when spelled out, the corresponding noun is thousandth. In general usage, thousandth is the standard term for the ordinal of one thousand.

In mathematics and computer science, the 1000th position is a common indexing reference, such as the 1000th element of a sequence or list. For example, the 1000th prime number is 7919, illustrating how ordinals identify specific elements in ordered sets.

A thousandth also designates a fraction: one thousandth equals 1/1000, which is 0.001 in decimal form. The metric prefix milli- denotes 10^-3, so a millisecond is 0.001 seconds. The per mille symbol ‰ expresses a quantity per thousand, as in 1 per mille being 0.001.

Usage and orthography vary by context and style. In prose, the spelled form is often thousandth when referring to the ordinal of one thousand, while numeric lists frequently use 1000th. The concept of a thousandth appears across disciplines, including mathematics, statistics, surveying, and linguistics, functioning as a standard unit of ordinal position and fractional size.

---