>Sergey,
>
>Yes they do, that's why the final result is controlled by the least accurate value involved in the calculation.

David,

That's not what I was refering to. Are you sure that imlicit error in the result of following calculation is 0.00005 not bigger?

3.1000 ± 0.00005 * 2.5567 ± 0.00005 is 7.9258 ± 0.00005

P.S. I maybe mistaken but I'm to leazy to go and read books on the subject. :-)