Expressing the Uncertainty (Reproducibility) in Measured Quantities Using Significant Figures
and the precision of measurement,
The mass may  be  simply  written as 2.2547 g, 
It is generally accepted, however, that measured quantities may be reported  in a way that only the last
All digits presented in this fashion,
The mass might be reported as 2.2547 ± 0.0001 g.
The mass of a dime
± 0.0001 ,
is implied.
Significant  Figures.
             measured on a balance designed to measure to the nearest   0.0001 g
                                                   was determined to be  2.2547 g .
( i.e. the right most digit)
                                                            is  uncertain ,,or  approximate. 
                                                  including the one uncertain digit,
 are termed