View source for Calculations involving significant figures

==Calculations involving significant figures==

Now that you've learned the importance of recording measurements to the proper number of significant figures, it is very likely that you will be doing calculations with these measurements. The type of calculations that you will most likely carry out are the following types of mathematical operations:

# [[Rules_for_addition_and_subtraction|addition]]
# [[Rules_for_addition_and_subtraction|subtraction]]
# [[Rules_for_multiplication_and_division|multiplication]]
# [[Rules_for_multiplication_and_division|division]]

It is important to know how to determine the proper number of significant figures in your answer AFTER you have completed mathematical manipulations of the measurements.

==Example==
Calculate the area of the table-top based on the following measurements:

* width = 50.996 cm
* length = 75.4 cm

To calculate the area of the table-top, the area would equal 50.996 cm x 75.4 cm. The calculator answer is

[[File:calculator2.gif]]

When you record the area of the table-top, should you record area = 3845.0984 cm<sup>2</sup> (<b>No!</b>)

The calculator displays too many figures. You need to know some rules in determining the proper number of significant figures of an answer which resulted from a mathematical operation.

After applying [[Rules for multiplication and division| the rules for multiplication and division]], the answer is <b>3.85 x 10<sup>3</sup> cm<sup>2</sup></b>.

==Content suitability==
BCIT courses:
<span class="pops">[http://www.bcit.ca/study/outlines/chem0011  CHEM 0011]</span>