How many sig figs when in decimals?

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Bryce Ramirez 1J
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Joined: Sat Aug 24, 2019 12:16 am

How many sig figs when in decimals?

Postby Bryce Ramirez 1J » Thu Oct 03, 2019 11:59 pm

How many sig figs are there for 0.0001? Because 1 is the last number and includes all the zeros, I thought it would be four, but it says that the amount is 1? What is the rule for zeros in this case?

SVajragiri_1C
Posts: 115
Joined: Thu Jul 11, 2019 12:16 am

Re: How many sig figs when in decimals?

Postby SVajragiri_1C » Fri Oct 04, 2019 12:02 am

In a decimal, you start counting sig figs at the first non-zero digit, whether it be before or after the decimal point.
So for example,
0.00345 has 3 sig figs.
3.034 has 4 sig figs.
0.0200 has 3 sig figs.

Tooba_1A
Posts: 11
Joined: Wed Sep 11, 2019 12:16 am

Re: How many sig figs when in decimals?

Postby Tooba_1A » Fri Oct 04, 2019 12:07 am

There would only be one sig figs, considering that the only significant number (1), only appears after 4 other zeroes, all of which aren't considered significant. Some factors that could have changed this outcome is there being another number before the zeroes, deeming all the zeroes after a significant and making it 5 significant figures. Additionally, if there had been zeroes after the 4, those would have been counted as well since they had occurred after an important number.

Tooba_1A
Posts: 11
Joined: Wed Sep 11, 2019 12:16 am

Re: How many sig figs when in decimals?

Postby Tooba_1A » Fri Oct 04, 2019 12:08 am

There would only be one sig figs, considering that the only significant number (1), only appears after 4 other zeroes, all of which aren't considered significant. Some factors that could have changed this outcome is there being another number before the zeroes, deeming all the zeroes after a significant and making it 5 significant figures. Additionally, if there had been zeroes after the 4, those would have been counted as well since they had occurred after an important number.

Pipiena Malafu 3J
Posts: 39
Joined: Fri Sep 28, 2018 12:27 am

Re: How many sig figs when in decimals?

Postby Pipiena Malafu 3J » Fri Oct 04, 2019 12:32 am

Long story short, leading zeroes (or zeroes before numbers other than zero) are never significant and thus there is only one significant figure for numbers like "0.002" and such.

J Medina 2I
Posts: 102
Joined: Wed Sep 25, 2019 12:17 am

Re: Significant Figures if last digit is 5

Postby J Medina 2I » Fri Oct 04, 2019 12:51 am

I was reading through the link "EVERYTHING YOU WANTED TO KNOW ABOUT SF" posted on the class website to review significant figures and was confused when I read that if a number ends in the number '5' and you are rounding, that you must round the number up or down to the nearest even number. I always thought a number ending in '5' always meant to round up. In the example given 2.65 turns into 2.6 when rounded. Is anyone else unfamiliar with this rule?

205154661_Dis2J
Posts: 109
Joined: Wed Sep 18, 2019 12:21 am

Re: How many sig figs when in decimals?

Postby 205154661_Dis2J » Fri Oct 04, 2019 1:01 am

I attended Step-Up session today and we went over sig figs. The UA told us to remember this:
1) Non-zero digits are always significant.
2) Any zero between two digits are significant.
3) Final zero or trailing zero in decimal portion ONLY are significant.
Hope this helps!


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