Sig Figs

[Chiara Berruto 1K]

I was marked down on the midterm for using incorrect number of significant figures and I was hoping someone could give me a quick overview of the rules so it doesnt happen again. Thanks!

[Jose Munoz 1D]

I use one rule the lowest amount of sig figs giving to me on the question is the sig figs I use to modify my final answer.

[Caitlyn Ponce 1L]

I think a short overview of Sig Fig rules are posted on the class website under the Math Assistance section.

[tmehrazar]

basically you can only give an answer with the same amount of sig figs as the number you used in your calculations with the lowest sig figs, this is because if you have a less precise number you can't report a more precise result

an example is if you used 4.000(4sf) and 5.0000(5sf) in your calculations, you would have to give an answer to three decimal places because that was your least descriptive number

0.005 has one sig fig because zeros past the decimal point but before a number don't count, but zeros past the decimal point and after a number do
0.0050 has two sig figs
50 has one sig fig because zeros after a number without any decimal point following them don't count either
50. has two sig figs because you know the number wasn't rounded to 50 but instead is exactly 50, because of the decimal

if you used numbers like 60.0(3sf), 400(1sf), and 0.70(2sf), you would give an answer to 1sf
so if your answer was 55.584 round it to one sig fig to get 60

lastly, do your calculations without rounding to the sig figs until the end, i like to put a line under the number I'll know i need to round to later based on the number of sig figs you have to have

hope this helps!