Significant figures requirement

[805601399]

Is there a specific number of significant figures that we will always adhere to in this class? Or does it change based on the numbers given in the question? If it does change, then do we use the largest number of significant figures present or the smallest?

[Lyndon Cope 2D]

Im not sure if it counts, for the Achieve homework I always answered using the correct number of sig figs which changes each problem. The general rule of thumb is to use the lowest amount of sig figs used in your calculations. For example if you calculated (152.5*24)/16.3 your answer should be to two sig figs.

[Vy Le 1G]

Hello,

There is no specific number we always adhere to in any class because each situation requires a different level of specificity. For instance, working with smaller units such as quantum mechanics may require more significant digits since it requires higher precision. However, a rule my previous high school chemistry teacher taught me was to always use the smallest amount of significant figures in the question. This may be tricky if the question phrases with trailing zeros so make sure to count those even if you don't use it to calculate!

Let me know if you need any further help!

[Abhinav Amanaganti 3K]

The sig figs required in a problem will always be related to the number of sig figs in the values being used in a problem. For example, if you are using molar mass from a periodic table to solve a problem (assuming all the other values are EXACT values, which means you disregard them for sig figs), you would use 4 sig figs for multiplication/division, or take sig figs to 2 decimal places for addition/substraction.

[Hannah Carsey 1B]

In terms of significant figures, you use the lowest amount of sig figs determined by the terms of the given values in a question for your final answer’s sig figs. Other than that, it is best to not round to sig figs until after you have completed the problem because rounding the values calculated in intermediate / middle steps might make your final answer value less accurate, as you want to calculate the most accurate final answer value.

[BriannaDis2C]

I believed that for this class, the amount of significant figures would be dependent on the problem. For example if your answer for a problem was 0.0020, there would be 2 significant figures but if your answer was 30100, there would be 3 significant figures. It really depends on the question.

[Lucy Farnham 1G]

Technically, the correct number of sig figs is different for each problem. So unless stated otherwise, you should use the correct amount of sig figs that the answer needs. However, if the question asks you to round to a certain amount of decimal places, it would be best to do that.

[Ainsley DeMuth 1H]

I have attended a couple different tutoring/step-up sessions with Dr Lavelle's UA's and they asked us to give our answers with the amount of Sig Figs used in the problem. For example, if three sig figs are given in the problem, I think it would be fair to give your answer in three sig figs. In these sessions, the UA's have also said the tests are often multiple choice so the sig figs will be predetermined. This is not confirmed by Dr Lavelle, but just information I have been given by the UA's that work with him.

[Coraly De Leon]

Hi,

I don't think so, in such cases, I'm pretty sure the question will ask to round to a certain amount of sig. figs.

[Justin_Choo_3J]

It is a general rule of thumb that one must use the least number of significant figures present in any number in the problem to display the solution. To exemplify, if the number with the least number of sig figs in a certain problem was 2 (e.g., 4.3 x 10^2), the final answer would have to reflect 2 sig figs.

[Neha Mukund]

I believe you adhere to the same amount of sig figs as the given number in the problem with the least amount of sig figs. I would round your final answer to the proper amount of sig figs at the very end of the problem.

[Simone Byun 1F]

When using significant figures, always refer to what's been given in the problem rather than a rule of thumb. From there, always use the least significant digits presented in the problem. You can always round to less places, but it would not make sense to add places (tens, hundreds, thousandths, etc).

[Alexis DeHorta 2A]

In terms of significant figures, you always want to take into account the smallest amount of significant figures a number will have in an equation.

For example,
3.0m x 1.45678m = 4.37034 = 4.4 m^2

Why is this 4.4m^2 instead of 4.37034m or 4.37 m ? Looking at the 3.0, we can see there are 2 significant figures. We take the lowest number in order to show how precise a number is. Otherwise, we would be compromising what the number is actually representing.
It is important to note that in most cases leading zeros and trailing 0's often do not count as significant figures unless there's a decimal.

Here are few more examples:
1) 1234 = 4 significant figures = nonzero numbers are
2) 102 = 3 significant figures = the zeros is in-between two nonzero numbers
3) 8.00 = 3 significant figures = because there is a decimal
4) 0.001 = 1 significant figure = leading zeros
5) 300 = 1 significant figures = because of trailing zeros
6) 1.222200000 = 10 significant figures = because of decimal

[Talia Tam 3L]

You use the lowest number of sig figs given by the problem, so it varies from question to question.

[Carmen Kim 3I]

I believe there is no specific number of significant figures that we will adhere to in this class. However, I learned that we should use the lowest amount of significant figures for the final answers. Also, we should not be doing the roundings in the middle of the process of getting the final answer because it could make a huge change in the final answer.

[Joseph Lee]

In terms of significant figures, you always want to take into account the smallest amount of significant figures a number will have in an equation.

For example,
3.0m x 1.45678m = 4.37034 = 4.4 m^2

Why is this 4.4m^2 instead of 4.37034m or 4.37 m ? Looking at the 3.0, we can see there are 2 significant figures. We take the lowest number in order to show how precise a number is. Otherwise, we would be compromising what the number is actually representing.
It is important to note that in most cases leading zeros and trailing 0's often do not count as significant figures unless there's a decimal.

Here are few more examples:
1) 1234 = 4 significant figures = nonzero numbers are
2) 102 = 3 significant figures = the zeros is in-between two nonzero numbers
3) 8.00 = 3 significant figures = because there is a decimal
4) 0.001 = 1 significant figure = leading zeros
5) 300 = 1 significant figures = because of trailing zeros
6) 1.222200000 = 10 significant figures = because of decimal

Thanks Alexis! This was really helpful. I took basic high school chemistry so I didn't really go into sig figs that much, so it's really cool that you took the time out of your day to explain it thoroughly like you did. So just to make sure, you always are supposed to use the smallest amount of sig figs in any given example? Also, for constants, are we allowed to round (like for the speed of light use 3 instead of 2.998)?

Thanks for the explanation again though!

[Shreya Arcot 3K]

The number of significant figures that need to be in our answer depends on the question; you want to use the lowest amount of sig figs given in the question. For example, given 5.0 x 1.2345, the answer would need two sig figs.

[Sam Forster 2J]

I believe it changes based on the question. If within the question the lowest amount of significant figures is two, use two significant figures in your answer, if it is three use three for your answer and so on and so forth. I don't believe that there should be a question with only one significant figure but if there is, you should use one sigfig in your answer.

[Sunny Hou 2I]

Hi! In general you would follow along the significant figures given in the question, and the sig figs of your answer would follow the the number with the least amount of sig figs in the question, (it is usually 3 sig figs though). So if you have 1.00 and 2.156 in your question, you would leave answers to 3 sig figs because 1.00 has the least amount which is three in this case.

[Rebekah Jung 1C]

The least number of significant figures given in a problem is used. In regards to multiplication and division, the least number of sig figs overall are used whereas in adding and subtracting the least number of decimal places is considered for sig figs. Also, I usually do not round in intermediate steps in order to keep the answer as accurate as possible.

[Neha Jonnalagadda 2D]

Generally, you should use the lowest number of significant figures that were used in your calculations. The actual number of sig figs depends on the problem though and should be a case by case scenario, especially with the Achieve homework.

[Maia Holmes Kueny 1C]

No. Do the lowest number of sig figs that are given in the problem.

[AndreyCastellanos 3H]

The sig figs required will always be the number of sig figs in the values being used in the problem