ninetieth

The term "ninetieth" refers to the ordinal number that comes after the eightieth and before the hundredth. It is derived from the cardinal number ninety, which represents the quantity nine times ten. In English, "ninetieth" is written as "90th." This ordinal number is used to denote the position of an item in a sequence, such as the ninetieth day of the year or the ninetieth place in a race.

The ninetieth is a significant milestone in various contexts, including education, where it marks the completion of the ninth year of study in a school or university program. It is also used in sports to denote the ninetieth game of a season or the ninetieth place in a competition. In historical contexts, the ninetieth year of a century is often referred to as the "ninetieth anniversary."

In mathematics, the ninetieth power of a number is denoted by the superscript "90," such as 2^90. This represents the result of multiplying the number by itself ninety times. The ninetieth root of a number is the value that, when raised to the power of ninety, equals the original number.

The ninetieth is also used in various cultural and historical references. For example, the ninetieth minute of a football match is often referred to as "stoppage time" or "injury time," where the game can continue even after the official ninety minutes have elapsed. In literature, the ninetieth chapter of a book may be a significant turning point or climax in the story.