順じゅん序じょ数すう

noun

ordinal number

Mathematical term for a number that indicates position or order, such as first, second, third. Contrasts with 基数 (cardinal number).

• 順じゅん序じょ数すうは集しゅう合ごう論ろんで重じゅう要ような概がい念ねんです。

  Ordinal numbers are an important concept in set theory.

• 第だい一いち、第だい二に、第だい三さんは順じゅん序じょ数すうの例れいです。

  First, second, and third are examples of ordinal numbers.