When to apply sig figs?

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DLee_1L
Posts: 103
Joined: Sat Aug 17, 2019 12:17 am

When to apply sig figs?

Postby DLee_1L » Wed Oct 02, 2019 10:03 pm

Do you apply sig figs to your final answer or every time you get a value? For instance, if I'm trying to find how many molecules of glucose there are in 63.5g, do I divide it by 120g/m (molar mass), round that number to 3 sig figs, then multiply by avagadro's number, then round the final answer to 3 sig figs again? Or do I just divide 63.5g by 120g/m, don't round that number, multiply by avagadro's number, then only round the the final answer to 3 sig figs?

805422680
Posts: 103
Joined: Sat Sep 14, 2019 12:16 am

Re: When to apply sig figs?

Postby 805422680 » Wed Oct 02, 2019 10:08 pm

No; you should only round your answer to the proper amount of significant figures at the end of the problem. You should never round off your intermediary calculations.

Jarrett Peyrefitte 2K
Posts: 102
Joined: Sat Aug 24, 2019 12:16 am

Re: When to apply sig figs?

Postby Jarrett Peyrefitte 2K » Wed Oct 02, 2019 10:09 pm

I think Lavelle has said if i'm not mistaken only to round sig figs on your final answer.

Sally kim 4F
Posts: 53
Joined: Thu Jul 25, 2019 12:17 am

Re: When to apply sig figs?

Postby Sally kim 4F » Wed Oct 02, 2019 10:09 pm

Hii!! I used to be confused about this also, but here's what I think. When you use sig figs, I believe that you only apply it to the final answer because if you keep applying it to every value you get, the final answer may not be as accurate.

Kendall 3H
Posts: 52
Joined: Wed Sep 18, 2019 12:18 am

Re: When to apply sig figs?

Postby Kendall 3H » Wed Oct 02, 2019 10:21 pm

I agree with what everyone else has answered. Sig figs should only be applied to your final answer, this way your final answer can be the most accurate. If you were to apply sig figs to every calculation, you would be doing a lot of unnecessary rounding that could change the final answer pretty significantly.


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