How to deal with significant figures in decimals with zeros.
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How to deal with significant figures in decimals with zeros.
Hi! So I am a little confused on the whole trailing zeros and zeros in decimal point aspects. My question is: how do I deal with significant figures that are inbetween numbers, but after the decimal point? For example, how many sig figs does 20.01 have?
Re: How to deal with significant figures in decimals with zeros.
Zeros, as in 20.01, do count as significant. In this example, 20.01 would have four sig figs.

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Re: How to deal with significant figures in decimals with zeros.
20.01 has 4 sig figs. As for your base question, when there is a decimal point, all trailing zeros are counted in the sig fig count. However, when there is no decimal point, trailing zeros don't matter. Any zero in between numbers counts, regardless if there is a decimal. So 2001 will also be 4 sig figs.

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Re: How to deal with significant figures in decimals with zeros.
I agree, 20.01 has 4 significant figures. If you wanted more clarification, Dr. Lavelle's website has this resource: https://lavelle.chem.ucla.edu/wpconten ... OUT_SF.pdf

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Re: How to deal with significant figures in decimals with zeros.
Anytime there is a zero between two significant numbers (nonzeros), it counts. So 20.01 will have four sig figs. Trailing zeros are ONLY significant if it is after the decimal point. So 20.010 for example would have 5 sig figs and 200 would only have 1.

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Re: How to deal with significant figures in decimals with zeros.
If there are zeros "sandwiched" between two numbers, they are always included when counting sig figs. So for example, 2001, 2.001 and 20.01 all have 4 sig figs. Zeros in front of the decimal never count, so .002 or 0.000002 only have one sig fig. And if there are trailing zeros, they only count if there is a decimal, so 2000 is 1 sig fig but 2000. and 2.000 have 4 sig figs. This is probably more than you needed but hope it helps

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Re: How to deal with significant figures in decimals with zeros.
According to the significant figures rules, all trailing zeros after a decimal point are considered significant. Additionally, all zeros that are located inbetween other nonzero figures are considered significant. In the example you provided, I believe that there would be 4 significant figures. The zeros would be significant as they are located inbetween the nonzero values of 2 and 1.

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Re: How to deal with significant figures in decimals with zeros.
Zeros that are in between integers are significant! In your example there would be 4 significant figures.

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Re: How to deal with significant figures in decimals with zeros.
There is a very good video on the website that goes over sig figs, I highly recommend it, it goes over all of this.

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Re: How to deal with significant figures in decimals with zeros.
20.01 has four sig figs. Whenever a 0 is between two significant digits, it's considered significant, regardless of whether it is before or after the decimal point. However, a trailing zero is only significant if it is after the decimal point.

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Re: How to deal with significant figures in decimals with zeros.
There's a rhyme my high school chem teacher taught us to remember this. If there's a decimal preceding that end 0 has meaning and if there are nonzeros on each side, that 0 must reside. So in the case of 20.01 since there is a decimal preceding the zero that zero is a sig fig and since there are nonzeros surrounding the zeros those zeros are sig figs.
Re: How to deal with significant figures in decimals with zeros.
Zeros inbetween numbers do count as significant figures. So, 20.01 has 4 significant figures. I always have struggles when determining if a zero is a significant figure. My tip is to look up the rules of significant figures and make a list with examples. With examples, I can compare it to other numbers as well because the concept is the same. To memorize these different rules, I usually make flashcards for each rule with an example.

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Re: How to deal with significant figures in decimals with zeros.
Hi Jenaye! I literally was so confused as well when I was working on the Sapling homework not too long ago. But riding off of what others have said, the numbers are important if they're between 2 integers. However, I am still having some trouble understanding the decimal rule.

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Re: How to deal with significant figures in decimals with zeros.
Here's a good link that explains what parts of a number are significant figures and which parts aren't. Also if you're ever really unsure as to the specific significant figures of certain number, this site provides you with a quick way to check if you got the number significant figures correct, after you've tried to figure it out yourself of course. https://www.calculatorsoup.com/calculators/math/significantfigurescounter.php

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Re: How to deal with significant figures in decimals with zeros.
Here is another helpful link I have found for this topic! https://users.astro.ufl.edu/~rlpitts/Si ... igures.pdf
Re: How to deal with significant figures in decimals with zeros.
Here's also a YouTube that really helped me understand sig figs! It explains the rules with addition, subtraction, multiplication, and division. https://www.youtube.com/watch?v=BmeImtwhfj8
Re: How to deal with significant figures in decimals with zeros.
I have a little list that helps me with sig. figs.
1. All nonzero digits are significant
2. Zero's between nonzero numbers are significant
3. Leading zeros are not significant
4. Trailing zero's in a number showing a decimal point are significant
1. All nonzero digits are significant
2. Zero's between nonzero numbers are significant
3. Leading zeros are not significant
4. Trailing zero's in a number showing a decimal point are significant

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Re: How to deal with significant figures in decimals with zeros.
Zeros that are in between significant figures, like the example you gave in 20.01, count as sig figs. As such, 20.01 has 4 significant figures. For reference, leading zeros that come after a decimal point don't count as significant figures.

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Re: How to deal with significant figures in decimals with zeros.
Thank you for all the replies! What about how to determine what sig fig should your answer be in an addition or subtraction problem?

 Posts: 92
 Joined: Wed Sep 30, 2020 9:36 pm
Re: How to deal with significant figures in decimals with zeros.
Once you have your answer, find the number with the least sig figs, and then apply the number of sig figs in that number to your answer.
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