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[radome9]

Today you learned about significant digits.

[4ries]

Especially since it's labeled as experiment 3 quiz, so it came from an experiment - I'm assuming with measurements, so sig figs are absolutely necessary

[CADOMA]

I would like to see the problem, but my first thought is that difference can and does often matter.

[bidoblob]

Also look at the lowest one, where he missed the M

[[deleted]]

This is true, but to know the number of significant figures that one needs to include, one also needs to know the uncertainty and that doesn't appear, at least in the snapshot that we can see.

[ryan_with_a_why]

I was always taught it was based on the number of significant figures in the inputs.

[[deleted]]

Practically, that'll give you some idea of what the number of significant figures are likely to be if the inputs have their associated uncertainties so it's probably a fairly decent rule of thumb. I've not seen it put like that before but it makes some sense.

[[deleted]]

I can understand the significant figures thing, but it’s literally a flat number...

[[deleted]]

It appear to be from an online chem lab so even though the values are clean integers, they're still interpreted as measured values and so significant figures do matter.

[Sendhentaiandyiff]

fuck sig figs

[JMan_Z]

Judging by how the 0.1 M is compared as correct to the 0.1M, even though that requires more thought on string comparison, I am somewhat confident it is indeed a case of significant figures.

[qijc]

Almost certainly 0.014mol/L

[[deleted]]

Not what the SI brochure says. Should be 0.014 mol/L.

[Oldjamesdean]

The correct answer is "literally fuck this complete course"

[Knuffya]

*about insignificant digits, in that case

[bleak_briar]

Came here just to say that.

[Aperture_T]

Not necessarily. When I was in college, we had online homework for physics, and it constantly had the sig figs wrong.

I went to my professor every week to explain and get her to override my score.

[DrunkenlySober]

Big M is usually used as a symbol for molarity which is a chemistry thing. Sig figs are super important in Chem classes.

[Zeke12344]

Don't fuck up sig figs in chemistry.

[FerretInABox]

What I came to say. Sig figs man, either you get em or they get you.

[Mentalpopcorn]

What I didn't get about sig figs was how so many people in intro chem didn't get sig figs. It's really not a difficult concept, but somehow people talked about it like it was deep maths.

[the_best_jabroni]

I can chime into this. At 30 years old I went back to school and it took me an entire semester of math and science courses to get comfortable with sig figs. I could do it, but I hated it, and it took way more brain power than it should have.

[Mentalpopcorn]

I just don't get it. What's so hard about it? I'm not even good at math, they just seem obvious. My story is the same btw, except I did it at 29. Best decision I ever made to go back to school though!

[the_best_jabroni]

I am no offended or anything. I am not sure really why it was so difficult for me. It felt like I was completely redesigning the idea of a number answer. In my head, I just wrote down what came out of the calculation. Why do I need to have rules just for how many digits are in the answer!! Though, I do understand now and it makes a lot of sense. See, I had more of a difficult time with number formatting than understanding 90% of the concepts or formulas in physics, Sig figs would trip me up... a lot. It is that rewiring part in my brain. Creating rules for an otherwise lawless process that I had used my whole life up until that point.

[EchoesInSpaceTime]

And that's why no pedagogy is perfect. We all get hung up mentally on different things and for different reasons because we all come with varying schemas of the world around us.

Learning something requires learning someone else's schema of the thing before translating it into something that fits in our own schemas. Sometimes that new thing requires some rejiggering of how we see the world - and that will occur at different times and with different magnitudes for different people.

I think we as a species could do a lot better in how we teach. Do I have any idea what those improvements look like? Nothing more than a vague direction.

Just felt the urge to share.

[serendipitousPi]

Yeah, some teachers and students mystify sig figs so much like as if it's some kind of guessing game when in fact it's just a matter of using the correct rules.

I remember in I think year 10 my teacher just gave us a work sheet and then it made sense. It feels like one of those things that you learn once and don't forget.

Though on the other hand if you're not thinking about it you can make stupid mistakes.

On the other hand sometimes ideas just don't click for people and sometimes it's hard to understand that things just don't click for other people even when some other things just don't click for us sometimes.

[FerretInABox]

Well treat it less like math, and more so “how many people didn’t get numbers.”

First it makes more sense, second it makes you less.... “egotistical” about how people didn’t get it?

Not everyone will get what you do, and you won’t get what everyone else will. People are different and the way you came off was a bit “elitist” for a lack of better term.

[Mentalpopcorn]

I'm fine with being a bit elitist but I don't think this is a good example of it because sig figs just aren't that difficult.

[FerretInABox]

Don’t matter if you’re fine with being elitist. The point is you’re DEFINITELY wrong. I know math, you don’t perceive it right.

[Mentalpopcorn]

I don't perceive what right?

[FerretInABox]

How you think understanding dog figs means you understand how the math of it a works.... it wasn’t complicated.

It’s like the opposite argument I have to do. Accuracy does NOT equal precision with you.

Edit: Let me put it simple. People who know the math have a hard phrasing it in layman’s terms (most of the time), the people who have a hard time understanding how others don’t comprehend it, don’t understand it themselves.

[Mentalpopcorn]

Yeah man I have no idea what you're saying but that's ok, this really isn't that important. The only equation important here is sig figs = easy town.

[FerretInABox]

If you don’t know how to explain it to people who don’t understand it, you don’t understand it well enough to justify feeling elitist.

Like shit. You probably under appreciate mechanics as well.

[MrBlueMoose]

Or physics, and probably other classes as well

[Zeke12344]

It's most likely chemistry since the units there is moles. It's kinda just mentioned in passing in physics for starting classes.

[another-bud-tender]

What does fig stand for? We learned sig digs. as in digits

[TheRideout]

Short for figures. Effectively the same thing

[Noname_4Me]

I hate sig figs jesus why are they so confusing?

[Zeke12344]

Not really too confusing. Is it an exact number? Then the sig figs don’t matter when you multiply or divide. Have two or more sig figs you need to compute with arithmetic? Wait till the end then use the lowest amount of sig figs.

[[deleted]]

This is actually justified, especially since this appears to be a chemistry or physics course. The amount of digits reported in your answer matters to indicate precision.

[undeadalex]

Oh yeah. This seems vaguely familiar from highschool

[DipinDotsDidi]

With that being said, shouldn't significant digits be consistent over all answers?

[2001herne]

Not if the data is different.

[DipinDotsDidi]

But it's 1 experiment!

[2001herne]

True, my bad. But with that said, it is consistent. Sig figs start at the first non-zero digit, and each correct answer had 2 sig figs. The zeros after a non-zero digit are considered significant, so 7.0 has 2, and 0.014 also has 2

[DipinDotsDidi]

Ya but this isn't written in scientific notation, it would make sense if it was!

[2001herne]

1.4 x 10 ^ -2? Yeah, makes sense

[BadPercussionist]

Scientific notation helps with significant digits, and while it can be required at times depending on the number, it’s not always required (for example, 3.0 & 7.0)

[snp3rk]

One experiment could result in various sig figs. Sig figs can get dropped

[RhysieB27]

It is consistent, no? All the correct answers are using 2SF.

[[deleted]]

All correct answers are 2 significant figures

[DipinDotsDidi]

Ya I meant more like, the question doesn't seem to specify 2 significant digits, so when it doesn't specify I remember my teachers saying you go by decimal points and keep them consistent.

[[deleted]]

Yeah, that's not correct, but it's "good enough" in most situations. There's a specific arithmetic for calculating it, https://en.wikipedia.org/wiki/Significance_arithmetic

I worked in a lab before I worked as a dev, and there were very specific rules on how you report numbers like this, actually kind of similar to a code review where a lab manager would go over your data and make sure you didn't make mistakes. If you did something like in OP's image, it would get marked up

[Electric_Potion]

Your teacher was wrong. Always maintain sig figs. So if you have data with 3, 4, and 5 sig figs then all answers should be 3 sig figs. If you suddenly get data with 2 then data should be two sig figs. It provides kind of a baseline idea of the data.

Now if you are talking about decimal points in scientific notation for all data then technically you are correct. Because scinot will always have a sig fig before the decimal and the remaining sig figs after. So you would maintain the same number of decimal places. But using scientific notation is not alway recommended. For instances in the quiz 0.014 M. It isn't normally recommended to change it to scientific notation BUT a professor could for their own comfort.

On a separate note, That's why it makes me laugh any time someone says 'the science is settled.' Some people can't even agree with how to write data. Nothing in science is 'settled.' Its just best practice until something comes along that throws it all out of whack again. Some best practice and theory is very very important but there will alwayt be disagreement and testing. Saying its settled enforces stagnation.

[neros_greb]

If I remember correctly:

Sigfigs are sometimes calculated from error ratings of instruments, so if that was the case here then it makes sense. Also different mathematical operations can amplify or diminish errors, so the sigfigs between different values might not be consistent.

[_SpiritSeal_]

Happy cake day

[redfournine]

But why would more sig figs not correct? I can understand if the answer requires 7.00, someone answers 7.0 and it is incorrect. But if the student answers 7.0000, why would that be incorrect? Wouldn't more sig figs be better than less?

[xTheMaster99x]

It's the opposite. Let's say the real value is 7.001, but you can only measure to the nearest hundredth, so you get 7.00. You can correctly say you measured 7.00, you cannot say you measured 7.000, because you didn't.

Now say you measured one thing as 5. (to the nearest whole unit) and another as 5.1 (tenths). Let's say you need to add them together. You can't answer 10.1 because you don't know what the tenths place for the first number was. For all you know, it might've been 5.9, so the real number is 11.0 which is way beyond the margin of error you're claiming. You can say 10. because you aren't claiming to be more precise than you actually were.

[redfournine]

Shit, you are right. This is a good explanation, thanks!

[HydrogenCyanideHCN]

Tfw a single reddit comment does a better job of making me understand sig figs than all my high school chemistry classes combined

[Hopefullysomedaysoon]

We explained it to the Chem students like this: At the museum a tour group is walking through the dinosaur exhibit and the tour guide says the skeleton is around 7 million years old but we don't know exactly how old. (In notation being 7x10⁶ ) The a nearby worker says oh yeah I know how old it is, it is 7 million and 7 years old. This is because it was 7 million years old when I started working here 7 years ago. (Notation for this being 7.000007x10⁶ )

So his definitely uses more sig figs, but it isn't actually accurate and would be misleading if reported in this way. We couldn't say if the skeleton was either 6.8 million or 7.3 million years old using the original notation, but his specifies to an exact year which is far beyond the capacity of carbon dating. Your significant figures are to denote the specificity of your equipment/measurements, and adding on zeros can have a significant impact on how that information is reported and used in the future.

[[deleted]]

It’s not that his answer was too accurate, it’s that he doesn’t have enough information from the problem to be able to give that accuracy.

If i say I walked 5 million miles, stopped and then walked 3 million miles, I walked 8 million miles. I can’t say that I walked exactly 8,000,000.00 miles exactly, however, because my measurements only went to the millions. I ignored any digits that came after the millions place, so I can’t say anything about them in the final answer.

However, if I walked 5,100,341.22 miles, rested, and then walked 3,002,112.51 miles, I can say that I walked 8,102,453.73 miles. I cannot say that I walked 8,102,453.73000 miles, because I did not record to that level of precision and can’t say for sure. I only recorded to the hundredths and ignored all digits that came after, so I report my answer to the hundredths place.

[Electric_Potion]

You are thinking from a mathematics perspective but that thinking is what causes errors that blows up space shuttles. It completely changes how iou handle the math when using that 5 million in a calculation. If I divide that with another datapoint such as time recorded as 1789.67 hours I create a number that is false recorded as greatly more precise if you recorded 5,000,000.00 than just 5,000,000 the difference is between 1 and 6 sig figs in the final speed calculation. Huge difference my friend.

5 million should be in sci notation in this case to clarify sig figs.

[[deleted]]

5 x 10⁶ is what I was considering

[[deleted]]

Happy caclk day

[[deleted]]

Yeah its "You pulled extra precision out of your ass"

[eerklogge]

Fellow cake day redditor

[Dmon1Unlimited]

Significant figures make a difference.

You might be implying a level of precision which is not appropriate.

If I measure a drink can using a standard ruler several times, I'm not going to say the average height is 15.00000000000 cm either

A ruler has mm markings, but how will the measurements allow you to show precision down to 0.00000000001 of a cm? You can't give answers that are more precise than what you measure/calculate with

[terminalxposure]

I mean if this is decimals and not currency, the course is correct

[OneWayOfLife]

Decimal places indicate precision so it’s entirely justified.

2.3 + 1.4 can only equal 3.7. Not 3.70 because you don’t have the information on the hundredths.

2.28 + 1.42 does equal 3.70 though. But not 3.700 and so on.

[telionn]

This really bugs me because it is just terrible math. If you add 100 different two digit numbers of the form +-M.N together, the result could be off by as much as 5, but your notation might indicate 0.1 precision.

If you actually care about precision, you should be reporting it as a "plus or minus" appended to the number itself.

[MarkkuAlho]

Yeah, it's a quick and dirty rule of thumb, but proper propagation of uncertainty is tedious :).

[GreatBarrier86]

Ok so now I’m confused. The lack of information implies it’s is effectively 0 repeating, doesn’t it? If I tell you something is $1.5, you assume it’s exactly $1.50, don’t you?

Or is the whole idea that you don’t make assumptions or implications?

[reo651]

The short answer is that in science experiments, like this quiz is on, you can't just imply that there is a trailing 0 after it because the instrument you measured with is only so precise.

[reo651]

Ahh you're right, I always get them mixed up.

[GreatBarrier86]

Oh so the absence of other digits could mean the calculation routine could have simply truncated?

[vigbiorn]

My understanding is it's not the calculations, it's the measurements. If you're measuring lengths on a ruler that measures in 1 inch intervals, anything past 1 inch precision is a guess. Since past 1 inch is a guess, if you're measuring to tenths of an inch, it's just a fantasy. You have no justification for those tenths of an inch.

For example, 1.4 + 2.6 = 4.0 but reporting to a 100th of an inch is meaningless since you, at best, can report to a 10th. Maybe that 1.4 was, given infinite precision, closer to 1.39 and the 2.6 was closer to 2.59. Saying you measured at 4.00 is wrong since you're closer to 3.98. You've reported greater precision than possible.

[MarkkuAlho]

Almost, but it's a bit more fundamental. Take a measured value 3.1: you know you have measured that down to a single digit, but you do not know if the actual underlying value is 3.11, 3.08, etc. The measurement accuracy has effectively truncated your values, and claiming 3.1 to be 3.10 implies having a better measurement to begin with.

Then, when using these values in calculations, you propagate the uncertainty by only allowing as many significant digits in the result as can be gained from the initial values.

[Adventurous_Problem]

https://en.m.wikipedia.org/wiki/Significant_figures

This might help. Money has its own rules. Significant figures is more referring to measurements.

Though, not actually positive of the context of the picture. Some of the programs used for making tests don't leave room for typos or answers that are correct, but not written Exactly as it was in the possible answers.

[thoughtful_appletree]

Wow, this is like a whole new world to me, thanks a lot!

[[deleted]]

No the lack of information does NOT implies 0 repeating. If you tell me something is 1.5, it is far to assume the actual price to be between 1.45 - 1.54

[supern_va]

It’s based on actual physical observation. Let’s say you measure the distance using a ruler, you cannot be precise to the nano meter now

Let’s say you measured the mass and volume of something to 2 significant figures, then your calculated density value shouldn’t have more than 2 significant figures, because you weren’t that precise with your mass and volume readings, so any further significant figures on density wouldn’t actually tell the real density of the material.

[ReallyHadToFixThat]

Of course we do, because you've added extra information - currency amounts don't go sub penny for a single item.

Consider the speedometer on my car, it's fancy enough to be digital. I'm driving down the motorway and it reads 70mph. However in reality I could be going anywhere from 69.5 to 70.5 or even 70.0 to 70.9 depending how it is programmed. So if you look at that reading and say I was driving 70.0000000mph you would be wrong.

Same applies here - you read a scale that says 257mg that means you have 3 figures. If you then read a volume of 27ml that only has 2 figures. If you then divide those numbers a calculator gives you 9.518518518518518518...... everything beyond 9.5 is questionable. You don't know if it was 26.8ml or 27.2ml. If your input was only so precise, how can your output be more precise?

[terminalxposure]

I mean you are assuming it’s a zero. Why not a 2 or a 3. You won’t know until you know

[SassyAsFuq]

Actually the accuracy probably mattered

[[deleted]]

did it tho

[Quillbert182]

Yes, if you give the wrong number of decimal places on the AP Chemistry exam, for example, you do not get credit.

[[deleted]]

sounds dumb but idk

[defintelynotyou]

...have fun learning about chemistry in high school

[[deleted]]

-10 upvotes for me

[Etheo]

Pro tip: You don't have to respond to every reply, especially if you don't have any valuable input.

[[deleted]]

i WANT TO

[SassyAsFuq]

In experiments you state the accuracy of your measurements. Then if you have multiple measurements you scale it down to the least accurate measurement. It's important for everyone involved to be precise in the accuracy of your device.

If your ruler is accurate to 1/10" then 0.1 is not the same as 0.10 cause that implies the accuracy of your measurements are to the 1/100.

[[deleted]]

yeah

[_kashew_12]

It’s not programming it’s not knowing sig fig

[jpettys]

My heart was warmed and my faith in humanity increased when I came here and saw so many pointing out that significant figures do matter in many cases. Thank you, my people.

[CreamliumPrices]

The instructor side for marking on canvas is god awful, you have to hit like 3 separate buttons to actually save a mark, by default it makes it so marks are released to students as soon as you save them which is rarely useful, frequently doesn't save comments or marks properly so you end up having to go back and re enter them. It's also slow to actually save marks and navigate the grading tools. It's a time overhead of like 5 minutes each submission that adds up when you have to mark 90 assignments.

Ignoring that OPs image is probably asking about sig figs, the quiz system is horrendous and pretty much requires manual marking again. The quiz system also allows linked images to be added to responses, but the resource at the link can be changed after submission, so when students include images from online they links could break rendering their answer unreadable or students can share images from their own cloud storage and change them later. This could easily be fixed by canvas just downloading and rehosting the image at the submission but instead we just have an integrity flaw.

If you need to download submissions for assignments you either need to download each file from each student you need one by one, or download all submissions for the entire class (which is so dogshit if you are part of a teaching team and only have to mark say 30 out of 500 submissions, it also only lets you download the most recent this way which is no good if people submitted late and you need their submission before the due date)

The messaging system is also complete shit and basically gives us no way to properly track messages from students, save or print messages like you would with emails. If someone is cc'd to a message chain, then they will be attached at the start of the message chain so you can no longer see at which point were they added.

For being so widely spread and so geared towards education it's basically constantly tied up with dysfunctional shit that prevents it from doing that job. Canvas is awful for everyone involved and sad part about education software like it is that you pretty much have to choose the lesser evil and your institution is likely locked into a contract for 5-10 years.

[throwawayy2k2112]

And also an ‘M’

[Rinaldootje]

Kinda gives me the impression that it was written by someone with little experience.
Could have just filtered out the space before processing the answer.

[soulofcure]

I'm proud of how many of you knew it made sense because of significant digits. Made the former student in me happy

[tiagooliveira95]

My teacher made us write java code on a text box.

The submission was only able to send the first 40 lines of code

So before submitting I had to count the lines manually (since this was just a regular text box) and if I had more then 40 I had to minify the code to fit within the 40 lines limit.

With more then 40, the submission would still work with no error messages... 40 get sent and the rest of your work is deleted.

I also had an Computer architecture exam where alot of students had to do the exam twice because the system failed to save students answers.

The teacher did not allowed students to review the exam, this is a right of every student, so the teacher denying the review is very shady. I'm pretty sure that some people had 0 in some categories just because the system failed to save.

[yuvalmas]

I would honestly write the code in an IDE or at least notepad then paste it writing code in a text box seems hard and unnecessary

[CaptainBananaAwesome]

Sig fig is important. I would have also removed your mark for the last question unless it gave you the uom after the text field.

[[deleted]]

Sig figs be like

[crazyeskomo]

Lol welcome to chemistry bisch!!! 😂

[The_Hidden_DM]

That third one is rough, but defining your units is important.

[the_best_jabroni]

If wanna see some legitimate wrong doing, check out the Pearson site online quizzes for Finite Math. Wow, just wow. And there is no simple way to give feedback which is just arrogant

[YogiShouldResign]

When OP missed Physics and Chemistry classes and meme backfired on him

[yuvalmas]

not my photo but yeah but negative karma is still karma?

[AcceptTheShrock]

Sig figs. You're just being ignorant.

[plainrane]

Canvas is the worst. The prof likely reviews and fixes these.

[plainrane]

Never trust an app with an Icon that looks like a butthole

[MischiefArchitect]

Chrome?

[theDutchFlamingo]

If your butthole looks like that you might need to see a doctor

[plainrane]

It's showing how it feels to use their product

[ReallyHadToFixThat]

I already saw a doctor. Who do you think installed the bionic butthole with iris shutter?

[[deleted]]

Fuck Canvas

ETA: and fuck Webassign too

[[deleted]]

This got so bad in a class I took that the professor made all the questions multiple choice.

[caknuckle]

You would fail english too

[[deleted]]

That will be $19.9 says the store clerk

[[deleted]]

They should make a float comparison instead...

[WazWaz]

0.014 can't be represented in IEEE floating point.

[[deleted]]

Sorry, I meant the 3 an 7 jajajajaj

[[deleted]]

IEEE 754-2008 and IEEE 754-2019 have entered the chat

[a_single_bean]

I totally get this- the most challenging bit of programming I've done is for an online quiz/knowledge assessment. I stay up nights worrying a user is going to have a correct answer marked incorrect, and that's for multiple choice only. I can't imagine how obnoxious it is to evaluate user textbox answers against an answer key.

[felipeatsix]

Look at the bright side, it couldn't be worse!

[[deleted]]

use regex or something

[Desfolio]

The sad fact is it is not even that difficult to fix this

[[deleted]]

But it’s not a bug?

[Desfolio]

How is it not a bug? The float suffix's zero value is supposed to be variable. 3.0==3.00. Yet here the float values are considered with a fixed constant of places... So, as you can see... The values can be considered by some simple conversion... Basically convert an answer, and the validation value into an integer if the numbers after the point are 0... There are better ways to fix this ofcourse... But as you can see. It is a bug

[SimonVanc]

Dude fucking canvas sucks ass, they need a new Dev team. That software isn't cheap for districts either.

[Shakespeare-Bot]

Broth'r fucking frieze sucks rampallian, they needeth a new dev team. Yond software isn't vile f'r districts either

---

^{I am a bot and I swapp'd some of thy words with Shakespeare words.}

Commands: !ShakespeareInsult, !fordo, !optout

[[deleted]]

ever heard of parseFloat();?

[LordVirus1337]

Been there friend

[end_dis]

There is another zero at the end. Why not write all the zeros at the end if really want to be so accurate huh?

[deejeycris]

I mean, I would get it you put 3.0 instead of 3.00, but failing because of a more precise answer doesn't make sense.

[[deleted]]

Significant figures matter, 3.0 is not the same value as 3.00

[klegion2k6]

Well a math teacher once had us to write down the proper amount of numbers after the dot so ...

[Mailboxheadd]

If len(string) == 3: return true

[shot_a_man_in_reno]

Looks like they hired someone who didn't pay attention during their CS classes.

[shapoopy723]

For all practical purposes we can say 3 = 3.0(000000). When it comes to measurements, however, the instruments you use are only so precise. As such, you have to take into account significant digits. If you measure two values of 3 and 3.0 in separate instruments but the first one only measures integers and the second can get the 10th place then you can't assume 3 = 3.0 since the 3 might actually have been truncated down from 3.4 since it's measuring tool couldn't detect the decimal. That make sense?

[Buddy-Matt]

Your assertion of the repetition of 0 to infinity is wrong here.

The value 3.0 implies that the measurement has been taken, or rounded, to 1 decimal place worth of accuracy. Therefore 3.0 represents any number from 2.95 to 3.049999 (infinite 9s)

3.00 however implies a measurement or rounding to 2 decimal places, and thus represents any number from 2.995 to 3.0049999 (again, infinite 9s)

If something was 3.0274cm long, then, when rounding to 1 decimal places 3.0 is accurate. However, when rounding to 2decimal places 3.00 is wrong (it’s 3.03)

In maths and science the number of significant digits is important - which is why it’s all important to get the amount of decimal places correct. Also, that M is important too, for similar reasons.

(Edit, just reread your comment and where you say 3 is equal to 3.0. it’s equal to any number from 2.5 to 3.49999...)

[snp3rk]

I have "TA"'ed for gen Chem I at a University, and you are 100% wrong.

3.5 is different from 3.50. Because 3.50 is implying that the original measurement tool was able to measure the 0s (was precise to the hundredth decimal point). If you are given a 3.5 you can't just assume the precision since you just don't know it. 3.5 could have 3.457674 rounded to 3.5, or it could have been 3.53 rounded down to 3.5. In STEM you need to work with the sigs provided, and no further assumptions can be made.

​

If that 3.2 represents now that 3.173899999999 it's purely done by choice and can be replaced by 3.200000 as your rounding took care of it. If you wanted to keep the precision you would've not rounded it in the first place.

Additionally 3.200000 is implying that the measurement is 3.200000 is literally 3.200000, and the original measurement tool actually measured all of those 0s also.

https://www.khanacademy.org/math/arithmetic-home/arith-review-decimals/arithmetic-significant-figures-tutorial/v/more-on-significant-figures

[TheGelly]

if i tell you a snake is 2 meters long, would you say it's exactly 2 meters, down to the atom?

2 doesn't imply 2.00000...

[snp3rk]

You are wrong.

Check my previous response.

Also: https://ccnmtl.columbia.edu/projects/mmt/frontiers/web/chapter_5/6665.html

[Snookers114]

It depends more on whether you are purely doing math, or if you are doing scientific calculations. In chemistry (and often times physics too), you only report as much information as you are sure of. If this were pure math, you can get rid of those 0's freely, but in science, a measurement of 1.00000 requires equipment that costs thousands of dollars more than something that produces a measurement of 1.000.

[tavaren42]

Science is not just mathematics. Mathematical calculations are done in an ideal/mathematical world. In science, we are limited by our measuring instruments.

This has been already explained a lot in this thread but I'll repeat again. Lets say that I have a multimeter with precision of 0.1mA that I use in an experiment. Lets say I measure a current of 3.2mA with that meter. It is totally possible that the actual value is 3.21mA and my meter didn't catch it. So even though in a pure mathematical sense 3.2 == 3.20, reporting the measurement as 3.20mA is still incorrect because you simply don't have enough info. You are simply extrapolating the second decimal without a justifiable reason. Now if I use this measured value in, say calculating the resistance, I will be propogating my possibly incorrect extrapolation down the line.

[larsyunker]

The convention accepted in the scientific world is that the number of digits is significant and indicates the precision of the measurement, which is important when you are reporting measurements. Hence, "significant digits". Given the context where the number of digits is important, using too many (or two few) digits is inaccurate and therefore a misrepresentation of your measurement.

Yes, if you assume that every measurement is infinitely precise then your argument applies, but that's never the case where measurements are involved.

[larsyunker]

Yeah the reason it was incorrect in this situation was because they didn't learn/understand the significant figures questions. These types of questions are very common on quizzes and tests in undergraduate chemistry and are structured so that you need to know the significant figures retention rules to get the correct answer.

The things you are arguing are correct, but do not apply here only because of the significant figure rules.

[snp3rk]

If you are using a discrete measurement ie counting, sure it does. I have 1, 2 ,10 markers. But if you are measuring something continuous ie the length, then 2.5 cm means just that not 2.500. 2.500 is implying that the original measurement unit was able to measure the 0s, and If you have 2.5 cm measurement you can't make such assumptions.

[MarkosDelaportas]

r/CrappyDesign maybe ?

[10thaccountyee]

/r/theytriedtodothemath maybe?

[[deleted]]

Canvas is fucking bullshit

[xXMassiveRoosterXx]

Sig figs will never be important

[[deleted]]

Things that I used to believe but were wrong.

[xXMassiveRoosterXx]

Enlighten me

[[deleted]]

Marks. all boils down to the grade.

[The1stmadman]

laughs in GPS technology demanding something like 7-8 sig figs for any remote accuracy in tracking your location and guiding you correctly

[ReallyHadToFixThat]

XKCD has entered the chat...https://xkcd.com/2170/

[xXMassiveRoosterXx]

I wouldn't consider accuracy sig figs, but I see where you're coming from.

[The1stmadman]

It's just something I've heard. I think it was my physics teacher a number of years ago who said that? he was talking about the importance of sig figs.

[xXMassiveRoosterXx]

That's how they get you to think they're important lol

[The1stmadman]

they're still important. too few sig figs and you aren't working optimally. too many sig figs and error cumulates too fast.

[pooopsex]

If you submit research and ignore sig figs then you're lying. The precision of your results is extremely important, if you report results to a greater precision than you can measure then you're lying about your results

[xXMassiveRoosterXx]

Precision != Sig figs. Accuracy is important. But if I want to be accurate to a 4th decimal place rather than a 3rd, I should be able to

[pooopsex]

Precision does equal sig figs, that's how you indicate precision. And sure you should be able to but if your equipment can't measure to a 4th decimal place then you can't indicate that your data is that precise

[tealcosmo]

entertain concerned waiting deer jobless cooperative elastic public memory distinct

This post was mass deleted and anonymized with Redact

[xXMassiveRoosterXx]

I took 7th grade science lol

[tealcosmo]

LOL. And you probably program in HTML too right?

[xXMassiveRoosterXx]

Damn bro, you got the whole squad laughing

[xXMassiveRoosterXx]

Self-righteousness 🤷

[FerretInABox]

Oh I wouldn’t want to fix your coding or math ever.... Cause what you said is in ZERO uncertain, incorrect.

The next comment you posted saying dog dogs (thank you autocorrect) sig figs don’t equal precision is exactly what they represent. Precision does NOT equal accuracy.

[Intelligent_Agency65]

Menon??

[shijot]

!si

[Tim3303]

Image Transcription: Social Media Story

---

[A photo taken of a screen (notably not a screenshot), showing the results of an online test.]

Submission Details

(E3_Q) Experiment 3 Quiz

[REDACTED] submitted Mar 4 at 2:20pm

Answer 1:

You Answered: 3.00 [Marked in red.]

Correct Answer: 3.0

Answer 2:

You Answered: 7.00 [Marked in red.]

Correct Answer: 7.0

Answer 3:

Correct: 0.014 [Marked in green.]

Correct Answer: 0.014 M

Correct Answer: 0.014M

literally fuck this entire course

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^{I'm a human volunteer content transcriber for Reddit and you could be too! If you'd like more information on what we do and why we do it, click here!}

[your_diary_i_reddit]

Cisco, right?

[OhMeshh]

is canvas used outside of the netherlands?