View source for Rules for multiplication and division

The answer must contain the same number of significant figures as were present in the measurement with the fewest number of significant figures.

<b>Question:</b> A student measures the length of a table to be 120.2 cm and the width to be 29.5 cm. What is the area of the table. Express the answer with the proper number of significant figures.

<b>Answer:</b> 

Step 1: To obtain the area of the table, we perform the following multiplication using the calculator.

29.5 cm x 120.2 cm = ?

The calculator displays the answer to be 3545.9. The unit is in cm<sup>2</sup>.

[[File:calculator.gif]]

Step 2: Inspect each number and determine the number of significant figures in each number.

29.5 has 3 significant figures.
(This measurement has the fewest number of significant figures.)

120.2 4 significant figures. 

The measurement 29.5 limits the number of significant figures in the answer to 3 significant figures.

The answer is <b>3.55 x 10<sup>3</sup> cm<sup>2</sup></b>; 3 significant figures.

The answer has 3 significant figures because the length measurement is the measurement with the fewest significant figures (i.e. 3 significant figures). It limits the final answer to 3 significant figures.

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