# Significant Figures

Course:
Chemistry

Understanding Significant Figures (also known as “sig figs”) is incredibly important in Science! When you collect data, whether you’re doing Chemistry, Biology, Physics, or Engineering, you need to notice how precise your tools allow you to be. There should be one estimated digit in your data. This is where the idea of significant figures comes from - from measurement! Make a note of how precise your data is before you start calculating. Then you round off to the correct number of significant digits at the end of your calculations. Otherwise, you give people the wrong idea of how precise your initial measurements were. In this video, we’ll go over all the rules for determining significant figures. We also do examples of sig figs in calculations! We show you the rules for adding, subtracting, multiplying, and dividing. We even cover the advanced topics of significant figures in logarithms and when you raise 10 to a power.

Understanding Significant Figures (also known as “sig figs”) is incredibly important in Science.  When you collect data, whether you’re doing Chemistry, Biology, Physics, or Engineering, you need to notice how precise your tools allow you to be.  There should be one estimated digit in your data.

This is where the idea of significant figures comes from—from measurement.  Make a note of how precise your data is before you start calculating.  Then you round off to the correct number of significant digits at the end of your calculations.  Otherwise, you give people the wrong idea of how precise your initial measurements were.

There are 4 rules for determining significant figures:

1. Non-zero digits are always significant.
2. A zero is only significant if it is at the right end of a number AND after a decimal.
3. If a quantity is known to be exact, it has an unlimited number of significant figures.
4. When a number ends in zeros but contains no decimal point, the zeros may or may not be significant.

This video covers all the rules for determining significant figures, and includes examples of sig figs in calculations.  We show you the rules for adding, subtracting, multiplying, and dividing.  We even cover the advanced topics of significant figures in logarithms and when you raise 10 to a power.

Video: Significant Figures