This is not even squeak specific. Decimal floats not always can be
represented precisely in binary form:

http://en.wikipedia.org/wiki/Floating_point#Accuracy_problems



2008/2/17, cdrick <cdrick65 at gmail.com>:
>
> Hi,
>
> I noticed in my image (damien last beta so 3.10 - windows XP and
> Vista) that I have a strange bug when soustracting floats
> successively. Here is how I reproduce it in a workspace:
>
> 1 - 0.2 -0.05 -0.3 = 0.45 "true"
> 1 - 0.2 -0.05 -0.3 -0.1= 0.35  "true"
> 1 - 0.2 -0.05 -0.3 -0.1 - 0.10= 0.25  "*****false*****"
> 1 - 0.2 -0.05 -0.3 -0.1 - 0.10= 0.24999999999999995   true
>
> or again:
> 1 - 0.1 = 0.9  true
> 1 - 0.1 - 0.1 = 0.8 true
> 1 - 0.1 - 0.1 - 0.1 = 0.7 false
>
>
> Can somebody explain that or is it a bug ? I don't know yet if it's
> specific to my image, so does other have the same behavior?
> I can force the rounding of the result but find it strange.
>
> Cédrick
>
>
>
>
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