What do you mean by significant figures?

Explanation

Significant figures are those meningful digits that known with certainty ,
they indicate uncertainty in an experiment or calculated value , For example , if 15.6 ML is the result of an experiment , then 15 is certain whiile 6 is uncertain , and the total number of significant area 3.
Hence , significant figures are defined as the total of digits in a number including the last digit that repesents the uncertainty of the result .