Blog Post #2
(October 28, 2015)
On Friday, we talked about uncertainty in measurements, which brought along the wonderful method of scientific notation.
Scientific notation is a mathematical expression used to represent a decimal number between 1 and 10, multiplied by ten. It is also equal to the number of times the decimal places must be moved.
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| http://passyworldofmathematics.com/Images/pwmImagesFive/ScientificNotationTenB550x382JPG.jpg |
Talking more about uncertainty, different measuring devices have different uses and different degrees. This is what we call significant figures, or sigfigs for short.
There's five important rules for significant figures:
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| http://passyworldofmathematics.com/Images/pwmImagesFive/SignificantFiguresTwo550x442JPG.jpg Addition/subtraction and multiplication/division with sigfigs have rules to them as well. When adding/subtracting: the number of sigfig in the results is the same as in the measurement with the smallest number of decimal places. Multiplication/Division: the number of sigfig in the results is the same as in the measurement with the smallest number of sigfigs. |
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| http://chemsite.lsrhs.net/measurement/images/sigCalcRules.gif Also important to remember is the conversion chart of : |
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| https://heathermicrobiologyjackson.files.wordpress.com/2013/06/metric_prefix.jpg |
Other key terms to know:
Accuracy: Refers to the proximity of a measurement to the value of a quantity.
Precision: Refers to the proximity of being exact.
(crash course on significant figures and unit conversions)
I love the title of this post it describes my feelings perfectly about this unit! I also watch the Crash Course Chemistry videos before testing, but some of these diagrams I have not seen and they seem very beneficial! Thank you, and I may be referring back!
ReplyDeleteI too love your title, it explains my feelings exactly! All of your diagrams and videos are really helpful and I will be referring pack to this post when it comes time to study for finals.
ReplyDeleteThe significant figures were the hardest for me to understand this unit because it was the only concept that was completely new. All of the rules seemed very confusing at first, but after practice, they became easier to do. Thanks for the Crash Course video, they are always helpful!
ReplyDelete