[SOLVED]The importance of collage grades and hand calculation troubles - Page 1
Forum section: electronics / general

author: Shpeccy
author_rank: Contributor
timestamp: August 29, 2019, 10:13:04 am
content: Hi. I'm a 1st year ee student at the Faculty of Electrical Engineering at the University of Belgrade. I'm asking two questions in this tread somewhat related to each other.1)Recently I passed Electrical Engineering 101, which is a minor miracle of you ask first years, but with a six. Now I should be glad that I just passed but I'm somewhat not content because I know I could have done better. Basically, I should have aced this exam, but every time I plug in my numbers I calculate it wrong. There were maybe like 2 questions I didn't mess up. And it's all sorts of little dumb mistakes like plugging in wrong resistor values, Having -x and x being a negative value but but I don't plug it in as a negative. i think that paints the picture as the type of dumb mistakes I make when plugging in values. Now, we are not allowed to use calculators, in any subject, so all of these need to be done by hand and I just keep messing it up. Actually I screwed it up so bad that my grade basically fell from a 9 to a 7, and then a 6 at the oral part in which the professor looked me in the eye and said "Yeah, you can't calculate", which fair point I can't.I should just let it go because I still passed but it's bothering me because I can and should have done much better. There are a few things stopping me from annulling my grade:The subject is worth 7 espb points and if I annul it now I won't even enter second year, let alone stay on the countries budgetI'm not sure if the grades matter all that muchPeople look at me like an idiot. I don't mind playing the fool but I feel like they might be right on this one.So do grades matter? Will this low mark bite me back in the future?2)What can I do to mitigate my little calculation problem? It is kind of a big issue. I already practice without calculators handy and still mess it up on examsEDIT: I'd like to thank everyone for taking time to answer. I think I'll take the conventional wisdom to heart that grades don't matter, practice arithmetic more in my spare time and just move on.

author: IanB
author_rank: Super Contributor
timestamp: August 29, 2019, 10:36:25 am
content: Grades matter because they give you an objective measure of how well you are doing. They are like feedback on your progress. Poor grades give you an indication of where you need to do better.So here you have identified a problem, and you need to figure out how to improve. Asking for advice is a good first step.Could it be that you are rushing? Haste often leads to error.One way to avoid mistakes is to go over things twice. After you write down the answer to a question, always go back and check over it a second time. Go over every step carefully and double check what you have done.Other than that, practice is another way to reduce mistakes. Work on more test exercises and examples and set a goal of improving your marks each time.Keep in mind that if you make mistakes later on in your working life there will be bad consequences. So use this time now to work on your calculation skills and learn how to avoid such errors.

author: Rerouter
author_rank: Super Contributor
timestamp: August 29, 2019, 11:09:12 am
content: If they are dumb mistakes, that generally means they are easy habits to train out of, while you glossed over the exact kind of problems your trying to solve, it may be worthwhile to make the calculations work for you, there is more than one way to approach math, if the one you know doesn't work for you, there may be another method out there that does,Does not work in every country, but for these calculation based tests, It may be possible to have the teachers agree to let you bring in a sheet containing common formulas that you struggle with. e.g V=IR, as long as it is only formulas and not notes, they generally will not object. you can use this to write them out clearly for yourself.Grades in general can be worked around later in life, If your after a path that needs higher education, then it may matter more than if you jump straight in to a entry level position where they are not as fussy, If your curious, have a peek at what kind of jobs in the feilds your interested in are, and what kind of requirements they are asking for, ignore the years of experience, just look if there are certain levels of higher education, or just "know about X", this can help you figure out what may get you over the line when you put forward your resume.Myself, I absolutely failed English, top in my state for physics, 3rd for math, but really poor in English, and that is when I realized for my countries university score, the English mark is used before even math, meaning it dragged that score down to almost nothing. still just meant instead of going into university, I went into a technical trade that had enough overlap to later move into where I thought that uni course might take me. all without having to pay for uni.Edit: I should include, I have never had an employer ask about my grades, and rarely even if I hold certain qualifications, so If you can't do well, can you still reach a passing mark?

author: Shpeccy
author_rank: Contributor
timestamp: August 29, 2019, 11:44:22 am
content: Quote from: IanB on August 29, 2019, 10:36:25 amIt's kinda hard to use the excuse that I'm rushing when the ee exam is like, 3 hours. It's plenty of time. (Though time is a problem in some other subjects). I guess I'll have to specifically practice going over my work. What about the exam itself? Should I move on since i passed or retake it?

author: AndyC_772
author_rank: Super Contributor
timestamp: August 29, 2019, 11:51:46 am
content: Do you do anything involving arithmetic outside of an academic context?One of my activities outside of engineering is Records Officer for my local archery club. After every competitive event, I collect score sheets from all the competitors, check the adding up, and determine who has won medals. I also load the results onto a database.There's quite a lot of adding up to do on an archery score sheet; it records the score for each individual arrow, plus totals for each half-dozen and complete dozen, a cumulative total after each dozen, and a separate total for each distance. That's a lot of places where a mistake can be made (though it also makes it all the more apparent if one number is wrong).For 'serious' events there are certain cross-checks I have to do, and you'd be amazed just how many people don't seem to be able to add up. Kids have become totally dependent on their phones, but adults make plenty of simple errors too. There is an incentive to get it right - at a formal event, any invalid (incorrect) score sheets go in the bin. There's neither time nor opportunity to return them and have them corrected; the onus is on the archer to ensure the score sheet they submit is right.What I do observe is that, regardless of age, people who have had more practice and tend to score higher, also make fewer errors.Personally I can't believe that numeracy should inherently be correlated with the sort of physical, practical skill required to shoot accurately. That suggests to me that practice at completing score sheets has helped them get this right as well.Practice makes perfect. Who'd have thought it?

author: Shpeccy
author_rank: Contributor
timestamp: August 29, 2019, 11:55:35 am
content: Quote from: Rerouter on August 29, 2019, 11:09:12 amI have never thought about approaching math differently. Can't say I really understand what you mean by "make calculations work for you" statement, could you maybe run me through it a bit more.As for the formulas... I'm like 90% sure that they won't allow it, since they won't tell us on the test if we ask them but that's fine they are never that hard to memorize. Sucks for English score being a requirement for uni, here each university administered it's own test. For ee it was math and physics to get in, although I heard that's subject to change.So my grades will be important for Masters degrees? Will it be bad if my first year is kinda garbo?

author: tszaboo
author_rank: Super Contributor
timestamp: August 29, 2019, 11:57:38 am
content: Doenst matter. Your job now is to pass all the required exams, not to be first of the class. In university, there is a lot of internal politics, not enough time, and you are old enough to have real life effect you. 50% of people didnt finish the EE course when I was graduating. You just have to be in the group, which finishes. You will loose some friends, people will get desperate, burn out, have children, run out of money, and so on.University is tough, you need to be tougher. The next exam, maybe you are allowed to use calculator. Different professor, different faculty, and so on. Very important, get the info. About the teacher, about the exam, about everything. There were four teacher doing maths, and one had 70% of the students failing on his exam, because he was pain in the ass.So you had to:1 get the info about him2 have a sleepover in the university computer room, because the registration started at 00:01 across the whole universiy, so servers died3 press F5 rigorously until you could log in4 apply to the different group,5 pass the test as easily as a walk in a parkOr you didnt do it, and you were likely repeating step 1-5 the next semester. The end result is binary. You have a degree or you dont.

author: amyk
author_rank: Super Contributor
timestamp: August 29, 2019, 12:05:05 pm
content: To repeat what the others have said, practice is probably the best way to improve your arithmetic skills, but you need to do a lot of it, to the point that you memorise addition and multiplication for all 2-digit numbers.This site may help:https://arithmetic.zetamac.com/

author: soldar
author_rank: Super Contributor
timestamp: August 29, 2019, 12:32:36 pm
content: Quote from: Shpeccy on August 29, 2019, 10:13:04 amPractice. A lot. Go slowly. Very slowly. In the worst of cases you can check your calculations by doing them twice, preferably in different ways.

author: delfinom
author_rank: Regular Contributor
timestamp: August 29, 2019, 12:44:01 pm
content: Also when taking an exam, if you finish it with time left in the test taking period, go back and recheck everything. Don't just hand in the test because you filled out the problems once.

author: Shpeccy
author_rank: Contributor
timestamp: August 29, 2019, 01:01:28 pm
content: Quote from: amyk on August 29, 2019, 12:05:05 pmThis is probably the exact thing I need! Thank you very much!

author: Shpeccy
author_rank: Contributor
timestamp: August 29, 2019, 01:09:53 pm
content: Quote from: NANDBlog on August 29, 2019, 11:57:38 amIt's about the same situation here, except we have no idea which one of the professors are actually grading the exams, and in reality the professors have probably forced the assistants to do it. I theory all the professors from a subject oversee all the students, at least in the first year, and it's up to the professors to decide how they spit work of grading and like I said they probably just dump it to the assistants

author: bd139
author_rank: Super Contributor
timestamp: August 29, 2019, 01:16:51 pm
content: Sounds like you just need practice. We all screw up calculations. The best of us, which I'm not even anywhere near, expect to screw up 1 in 10 calculations. Historically when calculators were human the calculations would be done twice if critical for checking. You need to do that as well.Honestly though, you can do stuff incredibly quickly and accurately by hand in very little time with practice. But you have to practice a lot as with everything.Incidentally I learned arithmetic using the following text. It's an old one but a good one showing how to do things concisely:https://archive.org/details/in.ernet.dli.2015.463129When I was at school I was 3 years ahead of my peers thanks to that and the algebra book that came after it. I buggered myself on the calculus book though because it didn't discuss limits. Oops. Now I reach for the calculator occasionally but I usually know roughly what the answer is supposed to be without thinking too hard or writing things down. That always catches when I fudge something up on a calculator at least.Just remember this isn't just about passing exams as some people say but building a tower of knowledge on which you build your career through experience. This is one of the most fundamental, sharpest tools that will allow you to run rings around your peers.

author: rrinker
author_rank: Super Contributor
timestamp: August 29, 2019, 01:49:27 pm
content: Practice practice, and more practice - it's the only way to get the skills you need. And always check your work - best way is to write it all out. If you have plenty of time on the exam, even if showing your work is not required, do it anyway. And always carry units through - not just the numbers. That way, if you have a formula backwards, or something upside down, when the units cancel and you are left with volt-ohms when the expected answer is supposed to be in volts, you know you did part of the calculation wrong without even checking the absolute numbers.Others seem to think I've always had an easy time of math, at least up to advanced calculus, but if they had a machine to view a period in the past, they would see me reduced to literal tears trying to learn the times tables, going over it again and again with my Mom. But once past that hurdle - the world sort of opened up for me. I took extra math classes in high school, beyond what was required, along with calculus. Which helped greatly my first year in college.First semester, second year, I became a victim of the math department experimenting with the curriculum. Some sections spent more time on matrix math, some got taught Fourier Transforms. Second semester EE class was signals an systems - in which of course the Fourier transform plays a major role. Half of us were learning this for the first time, half were just getting a refresher. Exam results reflected this - a perfect double bell curve. Basically, half of us ended up having the privilege of paying the university to attend over the summer to retake the course to stay on track. Sometimes, there's just nothing you can do.Through it all, the one professor that the upperclass all warned us about as incoming freshmen turned out to be the best one in the department, and I ended up with a rather broad knowledge base instead of concentrating on one thing like digital or rf, because I took as many of that professor's courses as I could. The man could be an absolute horror - if you were lazy, didn't do your work, and didn't make any attempt to seek out help if you needed it. But put forth the effort, seek help if needed, he was exceedingly fair.Case in point, senior year my friend and I took one of his classes which sounded very interesting - speech synthesis and voice recognition. It was in the catalog as an undergrad course, and we had the required prerequisites. And we turned out to be the only 2 undergrads in the class. Started out OK, but the deeper we got, the more we realized we were in over our heads. And without the credit, we wouldn't have enough to graduate. There were few if any intermediate exams, just graded homework, which we always did, and usually did OK, because of putting in a lot of time on it. And then he announces the final exam will be an oral exam. We just looked at each other and basically said, see you back for another semester. After class, we spoke to the professor, asked if we could come together for the final instead of individually, and explained how in over our heads we felt. He allowed us to take the exam together, but said nothing else - we figured, we are not graduating. Our appointed time comes, we show up, we once again explain how so much of the material was just way over our heads. He sits back, and then asks, what is something you DID understand? So we rattle off a few of the topics we did get - at which point he starts asking us to tell him everything we know about some of those topics. My friend and I tag team back and forth talking about everything we learned regarding those topics until the professor stops asking questions. He again sits back, thinks for a little while, and then says "A-" We did wait until we were out of the room to jump up and down, realizing we were fine and would be graduating as expected now that we passed this course.Looking back, it's a funny anecdote from a specific period in my life. But at the time - it was deadly serious, being in a very real danger of not graduating with my class and having to take at least one more course and then graduating mid year with no big ceremony or anything. A disappointment to myself, and to my family. Despite the fact that my Mom would have never said anything - it was enough that I felt like I was letting her down. The end result was such a huge relief.All that - I will say, no one I ever applied for work with ever asked me what my GPA was. What degree I had, and the name of the university - but after that, no other details.

author: tggzzz
author_rank: Super Contributor
timestamp: August 29, 2019, 02:49:14 pm
content: Quote from: Shpeccy on August 29, 2019, 10:13:04 amThat sounds like you are being so fast you are careless.Some techniques to avoid that are to go more slowly, to explicitly write down the calculation in full before doing it, to recheck what you are about to calculate, to mentally estimate an approximate answer and compare it with your calculation, and if you have time at the end, to recheck what you have done.QuoteThat doesn't match the points above, in which case you may need additional or completely different techniques.QuoteThe first action is to admit there is a problem, because without that you cannot improve. You've already taken that stepIs it unclear to me whether your problem is because:you are simply carelessyou don't understand normal laws of arithmetic (especially operator precedence)you don't understand how to apply maths/arithmetic to solve a problem at handFWIW, the last was the problem with probability in my A-Level Pure Maths subject. I never managed toselectthe correct combination and permutation operators to get the right answer. Solution: choose other questionsNote that depending on you assessment of the above, different techniques are beneficial. fromhttps://en.wikipedia.org/wiki/Arithmeticmake sure you understand these terms and their consequences as embodied in operator precedence (BEDMAS/PEDMAS and similar).Addition is commutative and associative.Subtraction is neither commutative nor associative.Multiplication is commutative and associative; further, it is distributive over addition and subtraction.Division is neither commutative nor associative.Test for yourself: why do different calculators give different answers to 1+2*3= (hint: 9 is incorrect, 7 is correct).Incidentally, thehttps://arithmetic.zetamac.com/site may avoid considering thatnecessarypoint, by always inserting brackets. That would be to your detriment.

author: Nusa
author_rank: Super Contributor
timestamp: August 29, 2019, 03:07:15 pm
content: I suggest doing ALL your homework by hand to give yourself as much practice as possible for future tests. Do your finances by hand too. Do all your math in daily life by hand, just for the practice. Then recheck anything important using your calculator. If they don't agree, figure out where you went wrong, and why. Learn from your mistakes and try not to repeat them.As for the grade, so long as the grading was fair, I'd just accept the passing grade and move on. Setting yourself back a year is not worth it. Learn to do basic math without a calculator and do better in the future.There will be advanced work where calculators are required, since almost nobody uses lookup tables anymore (I grew up when slide rules were still a thing), but those classes will likely allow calculators during testing.

author: IanB
author_rank: Super Contributor
timestamp: August 29, 2019, 06:35:21 pm
content: Quote from: Shpeccy on August 29, 2019, 11:44:22 amI think you never want to go backwards. If you passed the exam take it as a lesson learned and move on. Try to do better next time.

author: rstofer
author_rank: Super Contributor
timestamp: August 29, 2019, 07:19:54 pm
content: There is sometimes a tendency to skip steps in the arithmetic like x=a-(-b) and drop one of the minus signs. It happens all the time. Don't skip steps! When you cancel things across the = sign or out of numerator/denominator, rewrite the equation. Prove to yourself that you didn't skip steps. Show every detail of the calculation.I went to college under the slide rule program. We mostly did all the math in our heads and then used the slide rule to get some extra digits (not many!). We kept track of powers of 10 because the slide rule didn't. I still do math in my head and it annoys my grandson (an ME major) that I have a close answer before he can turn on his calculator. Sometimes I give him a head start.In every case, draw a picture. You should have a reasonable guess at the answer before even starting to calculate. If I learned anything at all in college it was to draw a picture. Every single time! I can't even have a discussion about anything technical without having a pen in my hand and an engineering tablet in front of me. Draw a picture! At least you'll get an answer in the correct quadrant.

author: Rerouter
author_rank: Super Contributor
timestamp: August 29, 2019, 08:38:14 pm
content: Shpeccy would you be able to write up an example of some of the questions you reguarly get tripped up with.What i said about more than 1 way is that every few years a curriculum changes how students approach certain math problems often to the point that the parents of said kid can't interprit it without some practice of there own. It sounds stupid but there is more than 1 method to some of it. E.g. transposing equations.For transposing fractions in equations. For some of my trade classes other students, it took the teacher bringing in a magnetic white board with magnet letters and physically showing them how it worked to get them to an understanding that stuck.

author: SiliconWizard
author_rank: Super Contributor
timestamp: August 29, 2019, 11:08:01 pm
content: Hmm, I would've thought "collage" grades would have been more for kindergarten. Or maybe Art school.

author: coppercone2
author_rank: Super Contributor
timestamp: August 29, 2019, 11:21:08 pm
content: how much you agree with cost people is all that matters for short term successdon't worry if you kill someone, you are new. its how they do it

author: Shpeccy
author_rank: Contributor
timestamp: September 01, 2019, 08:16:56 pm
content: Sorry for not replying to everyone in the past couple of days, had ee 102 and math 101 exams. I have been monitoring the thread and took it slowly on the ee 102(or slowlierlyer then usual) and I'll probably pass ee 102 where previously I thought it was a lost cause because I might mess up complex arithmetic.

author: Shpeccy
author_rank: Contributor
timestamp: September 01, 2019, 08:27:55 pm
content: Quote from: Rerouter on August 29, 2019, 08:38:14 pmI'd mess up multiplication or addition of two number e.g 3+5 would be a 7 or 25*3 = 45 and i'd not notice it on my own. I'd have an equation like x -y and y would be like -5 but i'd write it as x-5 even though it should be x+5. I'd have like, for example a series connection of R1+R2 and given resistors values of R1 = 4 R2=2 R3=6 and plug in R3 for R2 (not that often but happened on this test) or my most frequent one flipping around signs, for now reason. In one line it's a plus in the other a minus like magic and I won't noticeEdit: Also on the oral I said 500mW is 5W but I did have like, less then a minute for that one. Oral is brutal on time even if it the questions themselves aren't hard

author: Shpeccy
author_rank: Contributor
timestamp: September 01, 2019, 08:42:14 pm
content: Quote from: tggzzz on August 29, 2019, 02:49:14 pmI'm not sure how what I said doesn't support my point. But fine I'll give an example: On the oral I said 500mW is 5W not half a watt and the professor also wrote the "n" in nano kinda badly from the back rows it looked like a micro(we are seated didn't choose the seat in the bcak row) so I put micro instead of nano and got an answer three orders of magnitude higher then it should have been. At that point the professor said I can't calculate. As for the watt one it was way off. There was one question in general number. Didn't mess it up. My problem specifically seams to be adding and multiplying numbers. I seem to forget how adding and multiplying digits works on exams.I don't have a problem PEMDAS. A part of Math 101 is group theory and would I be in for it if I didn't understand those there

author: tggzzz
author_rank: Super Contributor
timestamp: September 01, 2019, 09:31:35 pm
content: Quote from: Shpeccy on September 01, 2019, 08:42:14 pmThat's neither an arithmetic problem nor a "hand calculation" problem.QuoteWhen I went through such exams in the UK, you got marks for having the right process/concepts and also marks for the right answer. If you cockup the arithmetic leading to an answer, you still get the marks for the process/concepts. If there are four steps in getting to the answer and you screw up one, you can still get 75% of the marks. But if you omit explicitly stating the steps, you can't!That's the reason it is so important to "show your reasoning".QuoteYou have specified where you think you need to concentrate your efforts.

author: Kilrah
author_rank: Unknown
timestamp: September 01, 2019, 09:33:25 pm
content: The grade itself doesn't mean much - the problems with basic maths do as order of magnitude calculations are the base of an engineer's job.Watch the EEVblog debunking videos - SO many times determining the feasibility of something is down to a 2 minute napkin calculation. If you regularly get that to an order of magnitude or more wrong and believe the result you'll end up with one of those bullshit kickstarters that you believed in because of a calculation error but gets shot down in flames by anyone able to do 1+1.So basically you need to find a way to fix your calculation errors, or you'll have no chance in the field (well that's debatable since those kickstarter owners can usually pay themselves and their engineers well enough for a while, they just have to move on to the next every couple of years). Gets into ethics territory at this point.

author: Shpeccy
author_rank: Contributor
timestamp: September 01, 2019, 09:53:08 pm
content: Quote from: tggzzz on September 01, 2019, 09:31:35 pmI've probably expressed myself wrongly, mea culpa.Quote from: tggzzz on September 01, 2019, 09:31:35 pmProbably why he let me pass to be honest.

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 01, 2019, 10:01:54 pm
content: As others have said you’ll need to fix your issue. Calculations are what makes an engineer an engineer and not a Hand Waving Specialist. If you can’t get it right engineering may not be for you. Remember that people’s livelihood and lives may depend on you getting things right.

author: james_s
author_rank: Super Contributor
timestamp: September 01, 2019, 11:04:10 pm
content: Grades only really matter to the extent that you need to have good enough grades to graduate. Early in your career I suppose it's possible an employer might want to check your grades however I've never heard of any place I worked doing that. They might check that you went to the school you say you did and earned the degree you claim to have but beyond that they're not likely to dig. What does matter is your performance on the job, especially as you progress in your career. The degree is an item on a checklist that will help you in the door at companies that require one, but beyond that it is not really all that important.

author: m98
author_rank: Frequent Contributor
timestamp: September 01, 2019, 11:12:13 pm
content: Quote from: tggzzz on September 01, 2019, 09:31:35 pmHighly dependant on the professor and his exams. I had theluckto have one that regarded calculation/algebra errors as "fatal mistakes", so for example one single missed sign and therefore a totally different result let you fail the whole exam.Generally, just give your best in the exams in order to pass them and try to get good enough grades so you have the option of continuing to a master degree. There are just some people who suck at exams and make stupid mistakes in them, but I know from my own experience, this doesn't transfer to anything else.Regarding some of the other answers, as soon as someones life depends on quick-math-skills, your company is doing something wrong. That's how you end up with MCAS...

author: Mr. Scram
author_rank: Super Contributor
timestamp: September 02, 2019, 12:53:22 am
content: Quote from: m98 on September 01, 2019, 11:12:13 pmThey're not "quick-math-skills". If your calculations are that disastrous your output simply cannot be depended upon. Even with checking and rechecking it's a disaster waiting to happen.

author: tggzzz
author_rank: Super Contributor
timestamp: September 02, 2019, 05:46:46 am
content: Quote from: m98 on September 01, 2019, 11:12:13 pmI made the point earlier that the OP's source problem might be (amongst other things) carelessness or the inability to correctly apply the correct maths to a problem.The latter is not merely a "quick maths skill", it is fundamental to engineering.When I hit the latter (in permutations and combinations probability calcs), I have avoided being in a position where I had to do such calculations. The OP should consider similar actions.

author: AG6QR
author_rank: Frequent Contributor
timestamp: September 02, 2019, 06:51:25 am
content: Quote from: tggzzz on September 01, 2019, 09:31:35 pmThat is ONE reason it is so important to show your reasoning. Perhaps it's the most important reason while you're a student. But it's not the only reason.When you cease being a student and start being an engineer, it's rare to get partial credit for wrong answers. It doesn't matter why the answer was wrong. What's wrong needs to be fixed and made right. And you need to be able to fix it quickly and accurately.All working engineers make mistakes; the good ones don't trust themselves too much, and try their best to set up the processes so that their mistakes will be discovered early, before too many people will notice them, and before they become very expensive or difficult to fix.When you do find out that you made a mistake, it may be long after you've forgotten some of the details of what you were doing on the day the mistake was made. If you have your notes showing your reasoning and the steps you went through, this may make finding and correcting your mistake much easier. If you happen to be out of the office the day the mistake is discovered, the fact that you've shown your work in a way that your colleagues can understand may mean you get to enjoy your vacation without having them call you in anger, asking you to fix a problem over the phone.More importantly, if you showed your work properly, you might have found and fixed your mistake immediately, during the process of showing your work. Finding and fixing your mistakes by yourself, before anyone else sees them, will make others think you don't make so many mistakes. They'd be wrong of course, but then again, what's the practical difference between an engineer who makes almost no mistakes and an engineer who makes lots of mistakes, but catches them himself before anyone else sees them?At least once a month, often more than that, I "solve" a problem for a colleague without understanding much at all about the problem I'm "solving". When the colleague explains the problem to me, he'll have a sudden moment when he realizes where the problem is. Maybe this comes after I ask a naive question to try and understand what he's doing, or maybe it will happen without me saying a word or asking a thing. The process of explaining your logic to a newcomer is very often enough to expose the flaw in the logic.The clever reader will notice that I'm not contributing much at all during the process I've described above. My clever colleagues can often shortcut this process. You don't necessarily need a live colleague to listen to your explanation (though sometimes it helps). Merely preparing your explanation of the problem and your logic in solving it, while anticipating what questions your colleague might ask, can sometimes be enough.I'm a big fan of showing your work.And I'm a huge fan of having a rough idea of what your approximate answer will be before you do any detailed calculations. After you have the detailed answer in hand, ask yourself "does this seem reasonable?" If a circuit has more power coming out of it than what was put into it, something is wrong. If a voltage in a circuit is higher than the supply rail, you'd better have a good explanation for that (I'm fully aware that it's possible, but if your calculations show it's happening and you don't understand why, your work is not finished). When you look at a voltage divider, before doing calculations, figure out whether you've got a big resistor in series with a little resistor, or if they're about equal, and determine in your head about where the intermediate voltage should be. If you have two items in parallel, figure out which one is going to carry the lion's share of the current before you start crunching numbers.Those little "sanity checks" don't take much time. In fact, in the long run, they save much more time than they cost.

author: soldar
author_rank: Super Contributor
timestamp: September 02, 2019, 11:21:26 am
content: Quote from: bd139 on August 29, 2019, 01:16:51 pmYears ago I used to do celestial navigation reduction calculations by hand using log tables which needed interpolating. I would practice and practice and I go to be pretty good at interpolating the table values by eye. I could consistently reduce sight pretty fast and with few mistakes. It got to be purely mechanical and with little thinking involved. I had a form where values had to be computed and input and on and on until I got to the end. By doing it over and over it got to a point where I did not need to think or know why I was doing anything. Just rote computing and filling a form with pencil and paper.