In need of a math nerd

Discussion in 'Blazers OT Forum' started by Mediocre Man, Dec 11, 2013.

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  1. Mediocre Man

    Mediocre Man Mr. SportsTwo

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    I am pretty good at quick math in my head, and have taught my kids many tricks on how to do math quickly in their head. However, my son had a basic 5th grade math question that I could not figure out a trick for, so I was hoping someone might have one.

    The question was 117 divided by 13

    I know the answer because I did the math long hand, but is there a shortcut for a problem like this?
     
    Mediocre Man, Dec 11, 2013
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  2. Denny Crane

    Denny Crane It's not even loaded! Staff Member Administrator

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    Denny Crane, Dec 11, 2013
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    BoBoBREWSKI likes this.
  3. BoBoBREWSKI

    BoBoBREWSKI BURP!

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    Calculator shortcut says 9.
     
    BoBoBREWSKI, Dec 11, 2013
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  4. OSUBlazerfan

    OSUBlazerfan Writing Team

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    You can quickly think of a multiple thats close to 117. 10 comes to mind. 10x13=130
    130-117 = 13
    10-1 = 9
     
    OSUBlazerfan, Dec 11, 2013
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  5. 3RA1N1AC

    3RA1N1AC 00110110 00111001

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    yeah find a multiple close to it you know to then add or subtract 13s from it
     
    3RA1N1AC, Dec 11, 2013
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  6. 3RA1N1AC

    3RA1N1AC 00110110 00111001

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    like the 99 x whatever bar trick, bet them a beer you can beat a calculator

    multiply by 100 and then subtract the original number
     
    3RA1N1AC, Dec 11, 2013
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  7. BlazerWookee

    BlazerWookee UNTILT THE DAMN PINWHEEL!

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    130-13=117?
     
    BlazerWookee, Dec 11, 2013
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  8. e_blazer

    e_blazer Rip City Fan

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    Math must be hard for Wookees. All that hair covering their fingers and toes.
     
    e_blazer, Dec 11, 2013
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  9. julius

    julius Living on the air in Cincinnati... Staff Member Global Moderator

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    does that work for other numbers too?

    And how did you decide to do 10-1?
     
    julius, Dec 11, 2013
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  10. 3RA1N1AC

    3RA1N1AC 00110110 00111001

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    cant talk for him but it seemed to just happen to work out that way

    say 204/17

    17 x 10 = 170
    17 x 2 = 34
    170+34 = 204

    204/17 = (10+2)

    ive always done math like this in my head, always seemed like the easiest way to me
     
    3RA1N1AC, Dec 11, 2013
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  11. tlongII

    tlongII Legendary Poster

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    117+13=130

    That tells you the answer is 9 right there.
     
    tlongII, Dec 11, 2013
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  12. Hobbesarable

    Hobbesarable Cartoon Character

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    MM, You may like the following site link:
    http://mathforum.org/dr.math/
     
    Hobbesarable, Dec 11, 2013
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  13. MARIS61

    MARIS61 Real American

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    117 รท 13 = 9
     
    MARIS61, Dec 11, 2013
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  14. barfo

    barfo triggered obsessive commie pinko boomer maniac Staff Member Global Moderator

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    Very simple trick:

    add the digits in the first number (in this case 1+1+7 =9). There's your answer.

    There may be some cases where this doesn't work, but there are other tricks you can use then.

    barfo
     
    barfo, Dec 12, 2013
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  15. Denny Crane

    Denny Crane It's not even loaded! Staff Member Administrator

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    Quick: what's 17.3 trillion divided by 313.9 million?
     
    Denny Crane, Dec 12, 2013
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  16. Mediocre Man

    Mediocre Man Mr. SportsTwo

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    I have no idea, but whatever it is, it would be the same as 17.3 trillion divided by 4 according to barfo
     
    Mediocre Man, Dec 12, 2013
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  17. Eastoff

    Eastoff But it was a beginning.

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    That's ridiculous, I think you mean divided by 16
     
    Eastoff, Dec 12, 2013
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