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Mental math

  1. May 26, 2008 #1
    Has anyone felt as though they've no problem with fairly advanced mathematics on paper, but is horrible with even arithmetic in their heads?

    If so, does anyone have any ideas as how to improve your mental math?
  2. jcsd
  3. May 27, 2008 #2
    it's muscle memory like anything else. one has to "remember" that 2+4=6 that 16-9=7. do it more often and you'll become faster.
  4. May 27, 2008 #3

    Gib Z

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    Homework Helper

    I remember arithmetic that I intentially practice, like some square roots and things, but i have a few seconds lag when you give me something like 7 * 6 =]
  5. May 28, 2008 #4
    I would perception is key. I think you can increase the speed of your computation through of practice and also perception.if you can form your own links with on numbers relate ,i think you can optimize your processor.lol
  6. May 28, 2008 #5
    lol i think that's pretty vague lol lol
  7. May 29, 2008 #6
    There are tricks to use of course. You can break the problem up into easier parts. Ex:
    347 + 982 = (300+900) + (40+80) + (7+9) = 1,200 + 120 + 9 = 1,329

    Most of it is practice, I think. If you want to get a lot better at it, do worksheets again and again (different each time) until you stop making many mistakes.
  8. May 29, 2008 #7
    It is though; different people do better with different kinds of connections.

    For instance, the way that I initially remembered the definition of sine and cosine was not the SOHCAHTOA thing that most American students get, but instead I would envision a person traveling at speed 1 with angle [tex]\theta[/tex] in the x-y plane (with [tex]\theta[/tex] measured counter-clockwise from the x-axis as is the usual convention)

    Then [tex]\cos(\theta)[/tex] gives the speed along the x-axis
    and [tex]\sin(\theta)[/tex] gives the speed along the y-axis

    And this is how I remembered the above 2 facts:
    To me, the word cosine and the idea of the x-axis seemed masculine
    While the word sine and the idea of the y-axis seemed feminine

    Yeah, makes sense, right? I doubt that there is a person in the world who understand how that makes sense (it doesn't to me either)

    Some people associate numbers with feelings, some people with pictures, some with colors. Some times people just memorize facts until they can recall them.

    Whatever works for a person is what works.
  9. May 29, 2008 #8
    As far as the topic at hand: I'm absolutely terrible with numbers. I usually tell people that I'm a Math Major because I hate doing calculations. I was once in front of a class working out a problem about probability saying "oh no... I counted 12 terms before, but now I have 4*3=16 terms... did I make a mistake somewhere?" It was a good 30 seconds or so before someone pointed out to me that 4*3=12
  10. May 31, 2008 #9
    LOL, beautiful Luke.
  11. May 31, 2008 #10
    i know most people ,,know about pemdas order of operations.if its possible some mathmatician should develop an order like pemdas for all mathematics, so people who can remember catchy words and phrases can develop better math skills.its just why we have brakets in our phone number for ex.1-800-XXX-XXXX.we have bcuZ WE CAN COMPACT INFORMATION AND CONTAIN MORE .THINK ABOUT IT MY FRIENDS THIS CAN MABE CHANGE MATHEMATICS.LOL
    Last edited by a moderator: May 31, 2008
  12. May 31, 2008 #11


  13. May 31, 2008 #12
    If this guy isn't trolling, I'll commit ritual Japanese suicide.
  14. Jun 2, 2008 #13
    That, really helped. To remember the trig identities and other jazz I always have to draw a makeshift unit circle on my paper and scribble the x, y, and r sides of the triangle it forms and...yeah. Pain in the butt.

    It's a big relief to know I'm not the only one who has trouble with arithmetic. My trick for things like 17 +or- 9 is to round the closest number to 10, take it away/add 10, and add/subtract 1. If all else fails, I use my fingers and toes. :blushing:
  15. Jun 2, 2008 #14
    this topic has so much of that feel good factor i needed ! : )
  16. Jun 2, 2008 #15
    You obviously never took a history course or you would know about the Egyptian King Soh Cah Toa. He of course invented the trig functions,

    Sine Opposite (over) Hypotenuse
    Cosine Adjacent (over) Hypotenuse
    Tangent Opposite (over) Adjacent
  17. Jun 2, 2008 #16
    Ah, but the point of this thread is that not everyone learns best by memorizing mnemonics. Sure, they help a lot of people, and I occasionally find myself using that one (if the triangle is rotated all weird, the way I learned sine and cosine can be a little clumsy), but trying to teach with only mnemonics only helps some people.
  18. Jun 2, 2008 #17
    True, I actually prefer the unit circle myself, but I was trying to be a wise guy :-)
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