Flexi Says: In any measurement, the number of significant figures is the number of digits thought to be correct by the person doing the measuring. It includes all digits that can be read directly from the measuring device plus one estimated digit.To determine the number of significant figures in a measurement that someone else has made, follow the rules for counting significant figures.When measurements are used in a calculation, the answer cannot have more significant figures than the measurement with the fewest significant figures.Rounding is done when one or more ending digits are dropped to get the correct number of significant figures. Simple rules state when to round up and when to round down.
