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Chemistry Forums for Students => High School Chemistry Forum => Topic started by: burkehenry on January 21, 2019, 05:24:55 PM

Title: Significant Figures help (confirmation)
Post by: burkehenry on January 21, 2019, 05:24:55 PM

My professor posted the following question in a quiz.  How many significant figures does the solution to this problem have? 2.45 x (7.0 x 10^-4) = ?   I came up with a solution of 1.715*10^-3 or 0.001715.  If I understand significant figures correctly, this would have 4 significant figures.  4 however, was not one of the options for the multiple choice answers.  Answers were 1,2,3,or 5.  Can someone help me to understand what I am missing here?

Title: Re: Significant Figures help (confirmation)
Post by: Borek on January 21, 2019, 06:01:33 PM

Quote from: burkehenry on January 21, 2019, 05:24:55 PM

If I understand significant figures correctly, this would have 4 significant figures.

Please elaborate why 4.

What is the first and most simple rule about number of sig figs in the result?

Title: Re: Significant Figures help (confirmation)
Post by: Enthalpy on January 22, 2019, 05:47:17 AM

Why would the product be written as 0.001715 rather than 0.00171500000000 which has 12 significant figures?
How many significant figures in the problem's data?