Significant Figures
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 Posts: 50
 Joined: Wed Sep 18, 2019 12:16 am
Significant Figures
What are the rules for significant figures again? It's been a while since I've done this and I cannot remember how to determine the correct number of significant figures for a problem/how it would be written.
Re: Significant Figures
Here are a couple rules I found online:
Nonzero digits are always significant.
Any zeros between two significant digits are significant.
A final zero or trailing zeros in the decimal portion ONLY are significant.
Nonzero digits are always significant.
Any zeros between two significant digits are significant.
A final zero or trailing zeros in the decimal portion ONLY are significant.
Re: Significant Figures
I also read from the textbook
"When reporting the results of multiplication and division, identify the number of digits in the least precise value and retain that number of digits in the answer."
as well as
"When reporting the results of addition or subtraction, identify the quantity with the least number of digits following the decimal point and retain that number of digits in the answer."
"When reporting the results of multiplication and division, identify the number of digits in the least precise value and retain that number of digits in the answer."
as well as
"When reporting the results of addition or subtraction, identify the quantity with the least number of digits following the decimal point and retain that number of digits in the answer."

 Posts: 103
 Joined: Sat Sep 14, 2019 12:16 am
Re: Significant Figures
Generally, if a question is asking for you to add or subtract, you round your answer based on the value in your working with the least number of decimal places. For example, 33.567+2.1 = 35.7. For multiplication and division questions, you round off your answer based on the value in your working with the least number of significant figures.
Re: Significant Figures
JOtomo1F wrote:Here are a couple rules I found online:
Nonzero digits are always significant.
Any zeros between two significant digits are significant.
A final zero or trailing zeros in the decimal portion ONLY are significant.
My question: When you say 'any zeros between two significant digits are significant', do the two significant digits need to be on the same side of the decimal point?
Re: Significant Figures
505106414 wrote:JOtomo1F wrote:Here are a couple rules I found online:
Nonzero digits are always significant.
Any zeros between two significant digits are significant.
A final zero or trailing zeros in the decimal portion ONLY are significant.
what are trailing zeros in the decimal portion?
Re: Significant Figures
505106414 wrote:JOtomo1F wrote:Here are a couple rules I found online:
Nonzero digits are always significant.
Any zeros between two significant digits are significant.
A final zero or trailing zeros in the decimal portion ONLY are significant.
My question: When you say 'any zeros between two significant digits are significant', do the two significant digits need to be on the same side of the decimal point?
No I believe that they don't have to be on the same side of the decimal but I am not 100 percent sure of that.
Re: Significant Figures
melinak1 wrote:505106414 wrote:JOtomo1F wrote:Here are a couple rules I found online:
Nonzero digits are always significant.
Any zeros between two significant digits are significant.
A final zero or trailing zeros in the decimal portion ONLY are significant.
what are trailing zeros in the decimal portion?
Here is an example of trailing zeros " 175.00" and that number contains five significant figures.

 Posts: 50
 Joined: Thu Jul 25, 2019 12:16 am
Re: Significant Figures
Sarah Zhari 1C wrote:Generally, if a question is asking for you to add or subtract, you round your answer based on the value in your working with the least number of decimal places. For example, 33.567+2.1 = 35.7. For multiplication and division questions, you round off your answer based on the value in your working with the least number of significant figures.
Hi! I'm not sure I understand what you meant. 2.1 is the value with the least number of decimal places right? So how do you get 35.7 as your answer with 3 significant figures if 2.1 only has 2 significant figures?
Or does that just mean the number of decimal places in your answer should equal the smallest number of decimal places in the question? Thanks

 Posts: 102
 Joined: Wed Sep 18, 2019 12:18 am
Re: Significant Figures
Yes, your last question was correct. For example, if you were adding 3.5 and 2.11, you'd get 5.61; however, in order for the answer to be rounded to the correct number of significant figures, you'd have to make your final answer 5.6.
This is because the final answer must take the same amount of numbers behind the decimal point as the number with the least.
That was a little wordy, but to put it into perspective: 3.5 has one number behind decimal point, while 2.11 has two. Therefore, the final answer would have one number behind the decimal point, because one is less than two.
Hope this helps.
This is because the final answer must take the same amount of numbers behind the decimal point as the number with the least.
That was a little wordy, but to put it into perspective: 3.5 has one number behind decimal point, while 2.11 has two. Therefore, the final answer would have one number behind the decimal point, because one is less than two.
Hope this helps.
Re: Significant Figures
JOtomo1F wrote:melinak1 wrote:505106414 wrote:
what are trailing zeros in the decimal portion?
Here is an example of trailing zeros " 175.00" and that number contains five significant figures.
thank you so much!!
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