# Question about O notation

**URL:** <https://fortran-lang.discourse.group/t/question-about-o-notation/8219>\
**Category:** Uncategorized\
**Created:** [June 17, 2024, 1:58pm UTC](https://fortran-lang.discourse.group/t/question-about-o-notation/8219 "2024-06-17T13:58:33Z")\
**Posts on this page:** 1\
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**Author:** ![RonShepard](https://avatars.discourse-cdn.com/v4/letter/r/a3d4f5/32.png) [@RonShepard](https://fortran-lang.discourse.group/u/RonShepard)\
**Post date:** [June 17, 2024, 3:49pm UTC](https://fortran-lang.discourse.group/t/question-about-o-notation/8219/3 "2024-06-17T15:49:15Z")

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In mathematics, there are well-defined meanings for large O() and small o() notations that you can find described online or in textbooks, but when used in this way, it just means “order of magnitude.” O(`10**9`) means that the actual number is probably larger than `10**8` and smaller than `10**10`. It is not a specific approximation, and it is not a rigorous bound.

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