# \[RFC\] What should the arithmetic within the FixedPointNumbers be

**URL:** <https://discourse.julialang.org/t/rfc-what-should-the-arithmetic-within-the-fixedpointnumbers-be/46697>\
**Category:** Visualization\
**Tags:** package, colors, numerics\
**Created:** [September 16, 2020, 12:14pm UTC](https://discourse.julialang.org/t/rfc-what-should-the-arithmetic-within-the-fixedpointnumbers-be/46697 "2020-09-16T12:14:42Z")\
**Posts on this page:** 1\
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**Author:** ![kimikage](https://sea2.discourse-cdn.com/julialang/user_avatar/discourse.julialang.org/kimikage/32/14534_2.png) [@kimikage](https://discourse.julialang.org/u/kimikage)\
**Post date:** [September 16, 2020, 12:23pm UTC](https://discourse.julialang.org/t/rfc-what-should-the-arithmetic-within-the-fixedpointnumbers-be/46697/3 "2020-09-16T12:23:46Z")

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### Option 2. consistent with `Integer`

| operation | `Fixed` | `Normed` |
| --- | --- | --- |
| `+`, `-` | wrapping | wrapping |
| `*` | wrapping | wrapping |
| `/` | checked | checked |
| `div`, `rem` etc. | checked | checked |

The difference between this and Option 1. is `*` for `Normed`. This option improves the consistency between `Fixed` and `Normed` and the consistency with Julia’s `Integer` system.  
( **Edit:** There is no operation for `Integer` `/`, so it does not affect the consistency.)

This leads to overlooking the overflow in the multiplication of, for example, `N2f14` numbers, but `N0f8` and `N0f16`, which are often used in image processing, do not occur the overflow in the first place.

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_[View the full topic](https://discourse.julialang.org/t/rfc-what-should-the-arithmetic-within-the-fixedpointnumbers-be/46697)._