Sig Fig Rules

Addition and Subtraction :
1) Count the number of significant figures in the decimal portion of each number in the problem.
(The digits to the left of the decimal place are not used to determine the number of decimal
places in the final answer.)
2) Add or subtract in the normal fashion.
3) Round the answer to the LEAST number of places in the decimal portion of any number in the
problem.

Multiplication and Division
Multiply or Divide in the normal fashion.
The LEAST number of significant figures in any number of the problem determines the number of significant figures in the answer.