activity series     bond energy     bond lengths     calculator   common names   conversion factors: energy   conversion factors: length   conversion factors: mass   conversion factors: pressure   conversion factors: temp.   conversion factors: volume   covalent prefixes   density solver   diatomic elements   e-config. chart   element list   gas law formulas   Ka's of polyprotic acids   Ka's of weak acids   Kb's of weak bases   metric conversion chart   mole conversion chart   molecular geometries   organic prefixes   periodic table   periodic table (flash)   pH/pOH converter   polyatomic ions   pressure converter   SI units   solubility chart   solubility of salts rules   solubility product constants   stoichiometry chart   temp. conversion   temp. formulas   thermodynamic data   vapor pressure of water
How To Round Numbers

 Rule 1. If the digit following the last significant figure is less than 5, the last significant figure remains unchanged. The digits after the last significant figure are dropped. Example: Round 23.437 to three significant figures. Answer: 23.4 Explanation: 4 is the last significant figure. The next number is 3. 3 is less than 5. Thus, 4 remains unchanged and 37 is dropped. Rule 2. If the digit following the last significant figure is greater than 5, then 1 is added to the last significant figure. The digits after the last significant figure are dropped. Example: Round 5.383 to two significant figures. Answer: 5.4 Explanation: 3 is the last significant figure. The next number is 8. 8 is greater than 5. Thus, 1 is added to 3 making it 4. The 83 is dropped. Rule 3. If the digit following the last significant figure is 5, then 1 is added to the last significant figure if the last significant figure is odd. If the last significant figure is even, it remains unchanged and the digits after the last significant figure are dropped. Example 1: Round 3.35 to two significant figures. Answer: 3.4 Explanation: 3 is the last significant figure. The next number is 5. 3 is an odd number. Odd numbers round up when the following number is a 5. Example 2: Round 7.25 to two significant figures. Answer: 7.2 Explanation: 2 is the last significant figure. The next number is 5. 2 is an even number. Even numbers remain unchanged when they are followed by a five. The 5 is dropped.

 You may also find these related tutorials helpful
copyright© 2000-2021 - Tony Petras - www.sartep.com