Rounding when the last digit is 5

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Lily Kiamanesh 3D
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Joined: Wed Sep 30, 2020 10:09 pm

Rounding when the last digit is 5

Postby Lily Kiamanesh 3D » Mon Oct 12, 2020 11:52 am

Hi! In part 1C of the appendix on page A5, it states that "for numbers ending in 5, always round to the nearest even number. For example, 2.35 rounds to 2.4 and 2.65 rounds to 2.6," a rule that I had never before heard of. Is this how we are expected to round in this course? Thank you.

Crystal Yu 3C
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Re: Rounding when the last digit is 5

Postby Crystal Yu 3C » Mon Oct 12, 2020 11:54 am

I would assume that Professor Lavelle wouldn't be too strict about this rule since he hasn't mentioned it. I would still recommend asking him during office hours though, or see if he replies here! Personally, I've just been rounding up (2.35 to 2.4, 2.65 to 2.7).

Ria Nawathe 2B
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Re: Rounding when the last digit is 5

Postby Ria Nawathe 2B » Mon Oct 12, 2020 11:57 am

Yes, I think that's the rule we're expected to follow. On the Chem 14A website, Professor Lavelle posted "Everything you want to know about Sig Fig" under the Course Materials header, and the 2nd page summarizes rules for rounding, which include the nearest even number rule.

https://lavelle.chem.ucla.edu/wp-conten ... OUT_SF.pdf

Winzel Payumo 2K
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Re: Rounding when the last digit is 5

Postby Winzel Payumo 2K » Mon Oct 12, 2020 12:05 pm

I just heard of this rule last week, so it's a little weird for me to use, but since that rule is on his website, I'd recommend using it for now! Maybe we can ask our TAs or anyone who may know just to be sure.

Chem_Mod
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Re: Rounding when the last digit is 5

Postby Chem_Mod » Mon Oct 12, 2020 12:16 pm

Dr. Lavelle mentioned that standard rounding rules apply, so if the last digit ends in 5 or higher you will round up. The rule you mentioned does not apply. Hope this helps.

David Jen 3I
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Re: Rounding when the last digit is 5

Postby David Jen 3I » Sun Oct 25, 2020 2:40 am

For general problems, it is round up. But remember that when dealing with mols in empirical formula problems, we multiply to the nearest whole number.

nayha a 1L
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Re: Rounding when the last digit is 5

Postby nayha a 1L » Sun Oct 25, 2020 3:10 am

I know that a reply above stated that the rule does not apply, but just to confirm, I have been using the basic rounding rules on Sapling and have not had any issues. I had never heard of that rule either!


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