Decimal arithmatic, was Re: Python GUI app to impress the boss?

[Tim White]

Actually, using the implied precision...
0.7 is a number between 0.65 and 0.75 and
0.05 is a number between 0.045 and 0.055,
which multiplied together give a number between 0.02925 and 0.04125
or 0.035 +/- 0.006 if we are not loosing any precision.
This can be expressed as 0.04 with one significant digit (as were the 
original numbers) - but looses some precision.

Tim


Dennis Lee Bieber wrote:
>         When I took science classes, I'd have been dinged a few points if I 
> turned in 0.035 -- the rule was to report results to the same 
> significance as the inputs.
> 
>         0.7 * 0.05 => 0.0 in those science classes. The assumption here being 
> that the accuracy of measurements is such that the last supplied 
> decimal place is already an estimate -- one does not add places which 
> imply increased precision.