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### Sig Fig zero rules

Posted: Tue Oct 09, 2018 10:20 am
Hello! i am having some trouble remembering how sig figs work with zeros. For example how many sig figs are in 570, 500, 4.0, 40.0, .04, 0.04, .40, .0040? if anyone could help me out with this that would be greatly appreciated. Also if there are any other tricks for knowing how many sig figs there are please let me know!! Thank you!

### Re: Sig Fig zero rules

Posted: Tue Oct 09, 2018 10:24 am
Hi! The rules of sig figs are:
1. All non-zero digits are significant
2. Any zeros in between two non-zero numbers are significant
3. A zero at the end of a number without a decimal point is not significant
4. Any zeros at the beginning of a number are not significant
5. Final/trailing zeros in a number with a decimal point are significant

So in the examples you gave, 570 has 2 sig figs, 500 has 1, 4.0 has 2, 40.0 has 3, .04 has 1, 0.04 has 1, and .0040 has 2. I hope this helps!

### Re: Sig Fig zero rules

Posted: Tue Oct 09, 2018 3:45 pm

With values that end in zero but has a decimal point after it, you consider those zeros as Significant Figures.

For example, 500. and 4350. has 3 and 4 Significant Figures respectively.

Hope that helps!

If you do have questions regarding subtraction/addition and multiplication/division rules, just visit: https://lavelle.chem.ucla.edu/wp-conten ... OUT_SF.pdf

Good luck!

### Re: Sig Fig zero rules

Posted: Tue Oct 09, 2018 3:54 pm
Zeros in front of a non-zero number after a decimal point is not counted as a significant figure but the zeros after a decimal point count as a significant figure.

### Re: Sig Fig zero rules

Posted: Tue Oct 09, 2018 4:59 pm
In simple terms, the significant figures are all the numbers, including zeros, that follow the first non zero digit. The exception to that statement is a number like 70 or 200, which only has one significant figure unless specified with a period after the zero (70. or 200.) You would then include the zeros as significant figures.

### Re: Sig Fig zero rules

Posted: Tue Oct 09, 2018 5:01 pm
and just another sig fig rule is that if the decimal is 0.405, you would round your answer to 0.400 when needing 3 sig figs. When the last digit ends in five, would want to round the digit prior to it to the nearest even number.

### Re: Sig Fig zero rules

Posted: Tue Oct 09, 2018 5:07 pm
Pay attention to decimal points! Those indicate whether you count the zeros as significant figures in some cases.
For example 5000 has one significant figure, but 5000. has 4 significant figures!

I hope this helps!

### Re: Sig Fig zero rules

Posted: Wed Oct 10, 2018 12:08 am
All non-zero digits are significant
Zeros between non-zero digits are significant