arithmetic result shows a lot of unnecessary decimal places

[Oliver Hahn]

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When using the arithmetic plug-in some calculation results show a lot of unnecessary decimal places.

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Steps to reproduce,

1. Enable the arithmetic plug-in
2. Enter the following lines:

a=336/((1433600/64)/3600)
a=

3. Hit F5

a=54.00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000

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It would be nice to be able to limit the number of displayed decimal places.
Even better would be to be able to use functions like in the calculator plug-in,
So that the following would be possible:

a=(1 + 1/3) * 100
a=round(a)
a=133

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running zim 0.59 on Ubuntu