# Why assuming floating-point rounding errors are random is bad

**URL:** <https://discourse.julialang.org/t/why-assuming-floating-point-rounding-errors-are-random-is-bad/70647>\
**Category:** Offtopic\
**Tags:** float, rounding\
**Created:** [October 30, 2021, 3:40am UTC](https://discourse.julialang.org/t/why-assuming-floating-point-rounding-errors-are-random-is-bad/70647 "2021-10-30T03:40:14Z")\
**Posts on this page:** 1\
**Showing post:** 11

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**Author:** ![Sukera](https://avatars.discourse-cdn.com/v4/letter/s/ce7236/32.png) [@Sukera](https://discourse.julialang.org/u/Sukera)\
**Post date:** [March 29, 2022, 12:00pm UTC](https://discourse.julialang.org/t/why-assuming-floating-point-rounding-errors-are-random-is-bad/70647/11 "2022-03-29T12:00:11Z")

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> [@alequa](#):
>
> Can someone explain to me the deep meaning of it?  
> Thanks

> [@PSA: floating-point arithmetic](https://discourse.julialang.org/t/psa-floating-point-arithmetic/8678):
>
> Sometimes people are surprised by the results of floating-point calculations such as julia\> 5/6 0.8333333333333334 # shouldn't the last digit be 3? julia\> 2.6 - 0.7 - 1.9 2.220446049250313e-16 # shouldn't the answer be 0? These are not bugs in Julia. They’re consequences of the IEEE-standard 64-bit binary representation of floating-point numbers that is burned into computer hardware, which Julia and many other languages use by default. Brief explanation You can t…

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