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Math - Questions and Answers from our Archives  Significant
Figures  Date: 02/25/99 at 04:14:53 From: Em Subject:
Significant Figures  I am having trouble with significant
figures. I do not understand why:  a) 62.3 multiplied by 5.7 =
360, but 62.30 multiplied by 5.70 = 355.   The question says to
express your answer with an appropriate number of  significant
figures. Please help me, as I do not understand why we get  360
and 355.  Date: 02/25/99 at 12:15:12 From: Doctor Peterson
Subject: Re: Significant Figures  The idea here is that if one
of the numbers you are multiplying is only  accurate to two
significant digits, you can only trust two significant  digits
of the result, so you round to that accuracy.  When the numbers
being multiplied are given as 62.30 and 5.70, there  are 4 and 3
significant digits respectively, so you can keep 3 digits  in
your answer, 355. But when you are only given 62.3 and 5.7, you
should only keep 2 significant digit