October 09, 2024, 08:32:02 AM
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Topic: Non-significant digit rounding  (Read 690 times)

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Offline tk9

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Non-significant digit rounding
« on: September 21, 2024, 04:27:57 PM »
From what I've learned, we generally keep 1 non-significant digit in final values, but do we round the non-significant digit as well?

Let's say my value is 49.80877. I need to have 5 significant figures, so would the final value be 49.8087 or 49.8088 due to rounding?

Offline marquis

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Re: Non-significant digit rounding
« Reply #1 on: September 21, 2024, 04:43:24 PM »
Is this for a weight?  The number  of Sig figures was usually different for titrations.  We also had one manager who required us to write down all numbers displayed by the calculator. Found out different calculators used different algorithms and gave different answers.

Offline Borek

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Re: Non-significant digit rounding
« Reply #2 on: September 21, 2024, 05:09:53 PM »
From what I've learned, we generally keep 1 non-significant digit in final values

That's the first time I hear it.

The best approach I am aware of is to report correct number of significant digits (rounded) but to use full accuracy when doing calculations. Before calculators the rule was to use so called "guard digits" - say, two more than the number reported - but it lost sense eons ago.
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