Welcome To Signs101.com: Largest Forum for Signmaking Professionals

Signs101.com: Largest Forum for Signmaking Professionals is the LARGEST online community & discussion forum for professional sign-makers and graphic designers.

 


  1. This site uses cookies. By continuing to use this site, you are agreeing to our use of cookies. Learn More.

Who knows your fractions

Discussion in 'General Chit-Chat' started by Drip Dry, Jul 18, 2012.

  1. Drip Dry

    Drip Dry Very Active Member

    1,121
    1
    38
    Aug 11, 2004
    Long island NY
    Maybe I should have paid more attention in elementary school.

    How much is 1/5 of say 100.00 --------- 20.00 ? ----- Am I correct ?

    =========================================================

    Then how much is 4/15ths of 100.00

    I'm thinking 100.00 devided by 15 x 4 ======= 26.60 ? Am I correct ?


    Even if this is correct, can someone explain an easier way for different numbers

    Thanks
     
    Tags:
  2. 2B

    2B Moderator

    2,375
    146
    63
    May 5, 2011
    TX
    easiest way is to convert the fract to decimal and then multiply the decimal by the number

    1/5 = 0.20 * 100 = 20

    4/15 = 0.26666 * 100 = 26.67
     
  3. IronHawk

    IronHawk Member

    184
    0
    16
    Jun 28, 2012
    26.67 actually, unless I'm wrong here.

    4 over 15 = x over 100
    cross multiply
    15x = 400
    divide both sides by 15
    x=26.67

    same formula every time.... :thumb:
     
  4. Drip Dry

    Drip Dry Very Active Member

    1,121
    1
    38
    Aug 11, 2004
    Long island NY
    Thank You
     
  5. ironchef

    ironchef Very Active Member

    1,293
    17
    38
    May 1, 2012
    Miami, FL
    Wow that took me back to algebra class hahaha. I liked math in high school. It was English that had me in summer school lol
     
  6. round man

    round man Active Member

    637
    1
    0
    Oct 16, 2005
    back when the gerber 4b was in heavy use i had a fraction to decimal chart taped beside my monitor so I could see at a glance the decimal equivalent of a fraction to enter data to cut graphics in my first version of cadlink(now signlab) which was a 4b emulator for early pc's(286 era) like this one,....http://www.labeldotcom.com/Tips/Fraction-Decimal-Millimeter-Chart.aspx
     
  7. GAC05

    GAC05 Major Contributor

    5,031
    345
    83
    Dec 27, 2005
    Guam USA
    Set yourself free from fractions - go metric.....
     
  8. bob

    bob Major Contributor

    5,144
    259
    83
    Nov 4, 2005
    earth
    Surely you jest...

    A base 10 measurement system is rife with fractional results.Since 10 has only three factors, 1, 5, and 2, there's few calculations in that space that won't result in fractional results. Really clumsy fractional results since 10 can only be subdivided easily into 10ths, 5ths and halves.

    The reason, or at least one of them, that there's twelve inches in a foot is that 12 has factors, 1, 2, 3, and 4. It can be simply subdivided in to 12ths, 6ths, 4ths, 3rds, and halves. The probability of any calculation yielding an integer result is far more likely than with a base 10 system.

    The original question, how is 4/15 of 100 calculated has two primary approaches.

    One is to treat is as a ratio as was done in post #3. That would be 4 is to 15 as X is to 100, or restating it as 4/15=x/100. The solve for X. X=4*100/15 or 26.666...

    The other is to simply understand the notation. 4/15 means 4 divided by 15. Then the problem is stated 4/15 * 100/1=X. Which actually is a step in solving for X in the ratio statement but doing it this way doesn't require any pesky algebra. Albeit the trivial amount needed to solve the ratio.

    Actually the ratio approach is far handier. What if you had an image with an aspect ratio of, say, 23 high by 35 wide and you wanted to reduce the height to 14. What would the new width be? Just state it as a ratio...

    35/23=X/14 or 14*35/23

    It works the same if you want to make the width, say, 43. What would the new height be?

    23/35=X/43 or 43*23/35

    Thus endeth the lesson.
     
  9. GAC05

    GAC05 Major Contributor

    5,031
    345
    83
    Dec 27, 2005
    Guam USA
    I am not sure that I follow you bob.
    I must think on this as my math background is the metric equivalent of the North American Standard "zero".

    wayne k
    guam usa
     
  10. Cross Signs

    Cross Signs Active Member

    531
    12
    18
    Mar 30, 2006
    Largo fl

    WOW!!! Nice Bob.
     

Share This Page

 


Loading...