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Significant Figures

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Pizza Parker
Joined
Aug 22, 2018
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MCU
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Human Spider
Hey ZD,

I'm having a Chemistry test on Friday. It's on sig figs (significant figures). I'm still a little iffy the rules, especially for rounding.

Ok so I think that sig figs have a few rules:
  • All non-zero digits are sig figs.
  • Zeroes between two sig figs are also sig figs.
  • Trailing zeroes are only significant if they are to the right of the decimal.
  • Leading zeroes are not significant.

I think I can remember that (even if I can't see the rationale). But the rules for rounding are really confusing. What I'm told is that a number can only have as many sig figs as the number with the least sig figs (in multiplication and division). So when one has to convert 10 ounces into grams (1oz = 28.3g), they would multiply 10 by 28.3, and while they would get 28.3 from a calculator, they have to round it to 300 because 10 only contains 1 sig fig and so does 300.

So am I getting these rules right? Or are there more?
 
I'm pretty sure you would use three sig figs in the example you provided above because 10 oz. is treated as an integer value and therefore has an infinite number of sig figs. If you have something like that on your exam, you should ask the teacher if conversions are treated as integer values or not.
 

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