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Have "Silly" Mistakes in Math Ever Cost You Your Grade?

  1. Nov 23, 2015 #1
    Taking a Calc 2 course at uni and have been depressed since getting our midterms back last Wed.

    Had studied everything inside and out and ended up missing an A (got an A-/B+), due to very, very silly mistakes (of the arithmetic sort sometimes).

    This has been a problem that's plagued me all throughout HS and even previous college math classes. I've rarely gotten 100/100 on exams, due to some "stupid" mistake, such as leaving out a "-" (negative sign) or forgetting to copy the squared sign down to next line (despite clearly having it on the line above), etc. All of this is despite having understood the material and having known how to solve the problems and done them perfectly a zillion times in practice at home (and if not, at least going back and fixing the silly errors). So, it's super frustrating to lay an egg on an exam, due to a very silly error.

    This exam was different in that the professor was a bit more harsh in grading. So if you needed, say, a derivative to solve some lengthy problem and calculated it wrong from a silly error to start with, he'd dock you almost half or more than half of the exam points for that problem. This was regardless of whether your steps post-mistake were correct or not. It seemed from talking to two other students that those who got wrong a conceptual part of the problem (like literally not taking the right approach), but got their arithmetic and other "silly" stuff correct, had the same points taken off.

    That sort of depressed me. I knew what was going on and made some silly mistakes, but got the same grade as someone who got their basic math right, but made what I personally felt were "bigger" errors in taking the wrong steps to solve a problem.

    1.) Anyone gone through this and have any words of comfort and/or advice?
    2.) Worth speaking to the professor about it? My fear is that he'd think I was point grubbing, but it does seem unfair (to me, at least) that I'd score the same as someone with larger conceptual mistakes.
    3.) Do these errors ever go away for those of you in advanced maths? Do people in graduate school or senior level maths classes ever make "silly" mistakes (again, such as forgetting a negative sign or forgetting to distribute a negative inside of parentheses)?
    4.) In the big picture, should I just forget about it and realize I made some silly mistakes and not sweat it?

    (One final thing to add to what I mean by a "silly" mistake is that you clearly knew how to do it, but just made a mental, copying, or even "reading - as in misreading own writing - error vs. not knowing how to do a simple operation.)
  2. jcsd
  3. Nov 23, 2015 #2


    Staff: Mentor

    Different math profs have different standards. One of my profs whom I got to know socially long after I was out of college said that he graded problems on a binary scale -- correct answers got full credit, incorrect ones got no credit. Although he probably doesn't represent the majority of math professors, it's possible that you'll come in contact with another who takes this point of view.

    The best advice I can give you is to go back over your work and see that it makes sense. You might have to balance getting answers to all of the problems, with some of them incorrect due to haste, versus doing most of the problems, and taking time to go back and check for sign errors, forgetting to bring down an exponent, and so on.

  4. Nov 23, 2015 #3
    A mistake is a mistake. I actually have lost a letter grade in a class because of stupid mistakes on an exam (arithmetic usually), and that on the final exam can kill you. If you want, it can't hurt to talk to the professor, but be sure not to argue.
  5. Nov 23, 2015 #4


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    Staff: Mentor

    Two tricks that might help:
    1.) If possible, make a back-of-the-envelope calculation beforehand!
    Therewith you should recognize major deviations.
    2.) Try to use units!
    A problem expected to measure a velocity shouldn't have kilogram as a result.
  6. Nov 23, 2015 #5
    I'm sorry, but if you make a mistake in a real workplace, then this might cause disastrous things. For example, think about the Mars spacecraft that crashed because of a silly mistake by the engineers. Doesn't matter that they're silly mistakes and that the engineers clearly knew their stuff, they still crashed billion dollar machine. So if you lose half your points because of silly mistakes, then that's actually pretty generous compared to what happens in real life situations!

    So what to do now? Well, you'll need to develop some strategies in order to minimize the chances of making stupid errors. This could consist of:
    1) Making a general estimate or picture and see whether your end value agrees
    2) Find some way of double checking your final answer
    3) Go over your calculations two or three times
    4) Make use of units and other helpful tools
  7. Nov 23, 2015 #6
    I will have to say this, if it happens to apply to you: do not be one of those people who leaves before the testing period is done. I cannot for the life of me figure out why people turn in their tests as soon as they finish or after only checking it once. You've already signed up for the time slot the class is is. You might as well keep checking your work until you are 100% confident in it. Yes, that means checking over every line 5-6 times if you have enough time. Once, I went over a test 4 times before I realized there was another question on the back of the last page.
  8. Nov 23, 2015 #7


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    You do need to learn how to do work correctly and to be able to find mistakes when you make them. Grading standards can vary. Sometimes a simple mistake early on might render a problem pointless. When I'm grading, those kinds of mistakes will unfortunately cost students quite a lot, even if I realize it was just a dumb mistake. It's also possible that what you see as a dumb mistake might be seen by your professor as a conceptual blunder. Even if you know what you're doing, you have to be able to effectively communicate that to whoever is grading your work. It's not always obvious what a student is doing.

    I made a bunch of silly mistakes on an exam once, and even after going over it several times before turning it in, I didn't catch them. It was very frustrating to lose points for stupid reasons. I found it was better to slow down and carefully work through the problems rather than worrying about time and racing through problems quickly. After writing down a line of work, I would check it right then by recalculating it from scratch. It was easier to spot mistakes in one step rather than one buried somewhere in the middle of all of my work, and I found I quickly stopped making dumb mistakes to start with.
  9. Nov 23, 2015 #8


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    This happened to me once in vector calculus. Did all the work right on one problem (10% of the exam grade) and at the end put ##9 \cdot 1 = 10##...the answer was ##9##. I took it back to the professor, asked about partial credit, and he said no. Pedagogically I don't agree with this, but what can you do?
  10. Nov 23, 2015 #9
    I used to get in trouble on that all the time. For me, it stopped when I started being more careful to be well-rested and calm during exams, because being tired and anxious makes me very sloppy in my work.
  11. Nov 23, 2015 #10
    I stopped making them by writing slower and neater. I know sometimes the exams are timed but I tend to take the whole time and make sure to take my time writing everything out to avoid those little errors. I still make mistakes because I don't know the complete answer but attempt it and get partial credit.
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