“The meaningful digits which are known with certainty in a measurement are called significant figures .” Significant figures of a measurement are decided by following rules- (1) All non-zero digits are considered to be significant figures. For example, if the length of a pencil is measured to be 5.32 cm. Then, there are in all 3 significant figures in the measurement. (2) All zeroes between two non-zero digits are considered to be significant figures. For example, in 2.06, there are in all 3 significant figures. (3) All zeroes after a non-zero digit are considered to be significant figures. For example, in 2.00, there are in all 3 significant figures. (4) All zeroes coming before a non-zero digit are not considered to be significant figures. For example, in 0.0023, there are only 2 significant figures. (5) If a number is represented as scientific notation i.e. in the power of 10 then the significant figure is decided by the co-efficient of the number. For example, in