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