Significant figures calculation

[Mel]

Erik Max Francis wrote:

> Chris Angelico wrote:
>> On Tue, Jun 28, 2011 at 12:56 PM, Steven D'Aprano
>> <steve+comp.lang.python at pearwood.info> wrote:
>>> Zero sig figure: 0
> 
> That's not really zero significant figures; without further
> qualification, it's one.
> 
>> Is 0.0 one sig fig or two?
> 
> Two.
> 
>> (Just vaguely curious. Also curious as to
>> whether a zero sig figures value is ever useful.)
> 
> Yes.  They're order of magnitude estimates.  1 x 10^6 has one
> significant figure.  10^6 has zero.

By convention, nobody ever talks about 1 x 9.97^6 .

	Mel.