The term significant figures refers to the number of important single digits (0 through 9 inclusive) in the coefficient of an expression in scientific notation . The number of significant figures in an expression indicates the confidence or precision with which an engineer or scientist states a quantity.

Significant figures are the meaningful digits known with certainity plus one which is estimated or uncertainthere are certain rules for determining the number of significant figures these are stated belowall non zero digits are significant for example into 85 CM there are three significant figureszeros preceeding to first non zero digit are not significant such zero indicate the position of decimal points does 0.03 has one significant figure and 0.0052 to has two significant figureszeros between two non zero digits are significant does 2.0 05 has 4 significant figureszeros at the end are right of a number are significant provided they are on the right side of the decimal points for example 0.200 gram has three significant figureslike this we can identify the number of significant figures in given number