Rounding: when and where?

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Fenared Ortiz 3K
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Joined: Wed Nov 16, 2016 3:03 am

Rounding: when and where?

Postby Fenared Ortiz 3K » Sat Dec 09, 2017 11:05 pm

So I am aware of the sig fig rules, but i am having trouble trying to figure out when to round and when to just do the cut off method. For example when i got an answer for a square root i got .000189737, and the answer was 1.89x10^-4. I was wondering if we put 1.90x10^-4 would be marked as wrong.

Alex Nechaev 1I
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Joined: Fri Sep 29, 2017 7:04 am

Re: Rounding: when and where?

Postby Alex Nechaev 1I » Sun Dec 10, 2017 12:11 am

It wouldn't be wrong to round up, since I'm pretty sure the rounding rules still apply to sig figs. Both would probably be acceptable.

204917020
Posts: 31
Joined: Fri Apr 06, 2018 11:05 am

Re: Rounding: when and where?

Postby 204917020 » Sun Apr 15, 2018 7:00 pm

It wouldn't be marked as wrong because rounding rules still apply with sig figs. As long as you didn't round earlier in the problem, it's okay to round your final answer while still following the sig fig rules.

Jonathan Marcial Dis 1K
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Joined: Fri Apr 06, 2018 11:03 am

Re: Rounding: when and where?

Postby Jonathan Marcial Dis 1K » Sun Apr 15, 2018 7:03 pm

When you're rounding you just have to stay constant. For instance, if I round my very first solution to the 3rd decimal place, round the rest of your solutions to the 3rd decimal place.

yazminedesan1F
Posts: 40
Joined: Thu Feb 15, 2018 3:00 am

Re: Rounding: when and where?

Postby yazminedesan1F » Sun Apr 15, 2018 8:05 pm

usually I round to however many numbers are in the question.

SamanthaGrohe1B
Posts: 31
Joined: Fri Apr 06, 2018 11:03 am

Re: Rounding: when and where?

Postby SamanthaGrohe1B » Sun Apr 15, 2018 8:25 pm

during AP Chem in high school, we were recommended to round to the smallest number of sigfigs presented in the question

Allen Chen 1J
Posts: 31
Joined: Wed Nov 15, 2017 3:04 am

Re: Rounding: when and where?

Postby Allen Chen 1J » Sun Apr 15, 2018 9:11 pm

If that was the exact value, then rounding up wouldn't be considered wrong since 7 is above or equal to 5 and therefore is rounded up

Tiffany Tufenkjian 1E
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Joined: Fri Apr 06, 2018 11:05 am

Re: Rounding: when and where?

Postby Tiffany Tufenkjian 1E » Sun Apr 15, 2018 9:21 pm

I usually don't round until I get my final answer.

Chem_Mod
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Re: Rounding: when and where?

Postby Chem_Mod » Sun Apr 15, 2018 11:18 pm

The correct thing to do is not to round until the end of all mathematical operation.

Salena Chowdri 1I
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Joined: Fri Apr 06, 2018 11:02 am

Re: Rounding: when and where?

Postby Salena Chowdri 1I » Wed Apr 18, 2018 9:03 pm

As mentioned above, don't round off until the final answer. Your answer would not be marked as wrong but maybe to be safe in parenthesis mention that number of sig figs you've rounded to. However, the general rule is round off to the lowest number of sig figs given in the question asked.

Maria Zamarripa 1L
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Re: Rounding: when and where?

Postby Maria Zamarripa 1L » Mon Apr 30, 2018 10:53 pm

When: at the end of solving the problem.


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