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### Sig figs confusion

Posted: **Tue Oct 01, 2019 12:41 pm**

by **Doris Cho 1D**

I'm having trouble determining how many sig figs should be in my final answer and there aren't any numbers in the problem to tell me the least amount of sig figs to use.

For example, in F5, I rounded the percentages to 4 sig figs but the answers have either 4 or 5 sig figs... is it just a trial and error thing where I see which numbers will add up to 100%?

### Re: Sig figs confusion

Posted: **Tue Oct 01, 2019 12:50 pm**

by **Shivam Rana 1D**

I also didn't know how many sigfigs to use; I went with 4 though. I think the more important thing is to make sure that the individual percentages add up to 100%. I'd also look at the number of figures on the periodic table you're using, but I'm not totally sure that is the correct way to determine the number of sigfigs that need to be present.

### Re: Sig figs confusion

Posted: **Tue Oct 01, 2019 12:57 pm**

by **Verity Lai 2K**

I usually use three sig figs if I'm not given any numbers to base the sig figs on, but the more sig figs you use, the more acurate your values are generally going to be.

### Re: Sig figs confusion

Posted: **Tue Oct 01, 2019 4:58 pm**

by **Clara Cho 2K**

I also was confused by F5 I started with 3 sig figs, but the answer key had 4 or 5. Which one should I go with?

### Re: Sig figs confusion

Posted: **Tue Oct 01, 2019 5:45 pm**

by **Donavin Collins 1F**

Can someone briefly explain sig figs? My current understanding is that it's when you round to a certain place (tenth, hundredth...), but this is a topic that I never really understood. Also, is there is certain area of chemistry where you use it frequently? Thanks.

### Re: Sig figs confusion

Posted: **Tue Oct 01, 2019 6:10 pm**

by **Katherine Brenner 3H**

Hello

I am having the same problem- Im never really sure how many sig figs to use in each question. I normally just use the amount that they give inside the question (if they give a specific number).

### Re: Sig figs confusion

Posted: **Tue Oct 01, 2019 6:17 pm**

by **Subashni Rajiv 1K**

Your answer should have the same number of sig figs as the given value with the smallest number of sig figs.

### Re: Sig figs confusion

Posted: **Tue Oct 01, 2019 6:36 pm**

by **Minh Ngo 4G**

If they give you a number in the problem, usually you would then round your answer to the sig figs of that number. If not, i think the sweet spot is 3

### Re: Sig figs confusion

Posted: **Thu Oct 03, 2019 1:10 am**

by **Sion Hwang 4D**

Your final answer cannot be more precise than the measurements taken and given.

Generally, however, if the problem does not specifically indicate any measurement with significant figures, I would go with two numbers after the decimal (i.e. 35.45 or 2.15).