Significant Figures/Ambiguous Presentation

Warning
Consider a number $n$ which is reported to $d$ significant figures, but which is larger than $10^d$.

Then there will be one or more zero digits between the and the decimal point.

Hence, when $n$ is written out in conventional notation, as a string of digits, it is not possible to determine by inspection exactly how many significant figures $n$ is being reported.

In order to avoid such ambiguity, it is recommended that such a number be expressed in scientific notation, as this then becomes clear.