Sig Figs

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Harmony Becerra
Posts: 32
Joined: Sun Jan 21, 2018 3:00 am

Sig Figs

Postby Harmony Becerra » Thu Jan 17, 2019 7:54 pm

Just to clarify.. And please correct me if I am wrong. Is the general rule for sig figs: for multiplication and division, keep the least amount of sigfigs that the problem has? For addition and subtraction: keep the least amount of decimal places that the problem has?

Philip Lee 1L
Posts: 30
Joined: Fri Sep 28, 2018 12:21 am

Re: Sig Figs

Postby Philip Lee 1L » Thu Jan 17, 2019 8:01 pm

Yes, that is correct! You should also keep in mind the sig fig rules when solving problems with log, such as pH problems. The number you get after applying log to a certain value should have a number of decimal places equal to the number of sig figs in the original value.

-log (1.0 x 10^-7) = 7.00

1.0 x 10^-7 has two sig figs, so your final answer must have two decimal places

Posts: 60
Joined: Fri Sep 28, 2018 12:29 am

Re: Sig Figs

Postby Theodore_Herring_1A » Thu Jan 17, 2019 8:43 pm

Yes, you are correct. If you are ever unclear, Dr. Lavelle has a very helpful page on his class site.

Joanna Pham - 2D
Posts: 113
Joined: Fri Apr 06, 2018 11:04 am

Re: Sig Figs

Postby Joanna Pham - 2D » Thu Jan 17, 2019 9:07 pm

Yes that is correct! I would not worry about significant figures too much for this class though. According to the TAs, they will not pay too much attention to significant figures this quarter, meaning they won't take off points if you use an incorrect number of sig figs. Unless the question specifically says to use the correct number of sig figs.

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