Significant digits in a float?

[Roy Smith]

In article <mailman.9594.1398818045.18130.python-list at python.org>,
 Dennis Lee Bieber <wlfraed at ix.netcom.com> wrote:

> in a physics or chemistry class the recommended result is
> 
>    1.1 * 2.2 => 2.4

More than recommended.  In my physics class, if you put down more 
significant digits than the input data justified, you got the problem 
marked wrong.

> (one reason slide-rules were acceptable for so long -- and even my high
> school trig course only required slide-rule significance even though half
> the class had scientific calculators [costing >$100, when a Sterling
> slide-rule could still be had for <$10]) <G>

Sterling?  Snort.  K&E was the way to go.