Expert: Paul Klarreich - 1/29/2008

Question
(3.200 x 10^3)(7.2 x 10^-5)
i must give the answer with the correct number of significant figures. Also, it must result in an answer that is off to the same number of significant figures as is possessed by the least precise term.

another question, this was a sample question with division -- it also involves significant figures. It said:
8.8 = 22 = 20 (1 SF in answer)
I don't get why it would equal to 20.

Answer
Questioner:   alex
Category:  Advanced Math
Private:  No

Subject:  scientific notations & significant figures
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Hi, Alex,

Question:  (3.200 x 10^3)(7.2 x 10^-5)
I must give the answer with the correct number of significant figures.

>> significant DIGITS is a better phrase.

Also, it must result in an answer that is off to the same number of significant figures as is possessed by the least precise term.

>> Your 'least precise factor' here [it's not a 'term'] is the 7.2 -- it has two sig. dig's.  

Your calculator will give 23.04 * 10^-2 which should be adjusted:

2.304 * 10^-1  << correct to Sci Not.
2.3 * 10^-1  << to 2 sig. dig's.

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another question, this was a sample question with division -- it also involves significant figures. It said:
8.8 = 22 = 20 (1 SF in answer)
I don't get why it would equal to 20.

>> Neither do I -- you have to send along the ENTIRE TEXT of the question.