Results 1 to 6 of 6

Math Help - how do you change a decimal into a fraction?!

  1. #1
    Newbie
    Joined
    Jun 2005
    Posts
    3

    how do you change a decimal into a fraction?!

    1.411411141144 -- how would you make this a fraction???
    Follow Math Help Forum on Facebook and Google+

  2. #2
    Site Founder Math Help's Avatar
    Joined
    Apr 2005
    Posts
    171
    1.411411141144= 1 + \frac{411411141144}{1000000000000}

    or

    \frac{1411411141144}{1000000000000}

    or where you looking for something more elegant in a form similar to \frac{223}{31}?
    Follow Math Help Forum on Facebook and Google+

  3. #3
    Newbie
    Joined
    Jun 2005
    Posts
    3

    Talking Ahhhhh

    WOWWW!
    thankyou soo muchh.... wow you're a lifesaver*
    Follow Math Help Forum on Facebook and Google+

  4. #4
    Site Founder Math Help's Avatar
    Joined
    Apr 2005
    Posts
    171
    by the way 223/31 is not the correct answer. I was only asking if you wanted something similar?


    By the way do you mean

    1.411411411 where 411 is always repeating or did you mean precisely 1.411411141144 as you wrote

    if you meant 1.411411411 then the answer is 1+\frac{137}{333}
    Last edited by Math Help; June 13th 2005 at 03:46 PM.
    Follow Math Help Forum on Facebook and Google+

  5. #5
    Junior Member
    Joined
    Apr 2005
    Posts
    35
    Yup, .411411 repeating forever is 411/999 which is 137/333. Notice that this works with every repeating decimal, just divide by a string of 9's of the same length as the repeating block. I found this out using a geometric series one day in proofs. Now it makes sense that any decimal with a repeating block is a rational number.
    Follow Math Help Forum on Facebook and Google+

  6. #6
    Super Member
    earboth's Avatar
    Joined
    Jan 2006
    From
    Germany
    Posts
    5,829
    Thanks
    123
    hallo,

    in addition try this more mechanical way to change repeating decimals into fractions:

    Example: Transform .45123123123... into a fraction:
    1. x=0.45123\overline{123}
    2. Multiply x by a power of 10, so that you get instantly repeating decimals:
    100\cdot x=45.123\overline{123}
    3. Multiply 100x with a power of 10, so that the first block of the repeating digits is before the point:
    100 \cdot x \cdot 1000 = 45123.123 \overline{123}
    4. Now substract:
    100 \cdot x \cdot 1000 = 45123.123 \overline{123}
    100\cdot x=45.123\overline{123}
    You'll get:
    99900\cdot x= 45078
    x=\frac{45078}{99900}
    Afterwards you may simplify this fraction if it is possible!
    x=\frac{45078}{99900}=\frac{7513}{16650}
    Follow Math Help Forum on Facebook and Google+

Similar Math Help Forum Discussions

  1. fraction into decimal
    Posted in the Algebra Forum
    Replies: 5
    Last Post: November 18th 2008, 06:48 AM
  2. decimal to fraction on TI-83
    Posted in the Calculators Forum
    Replies: 2
    Last Post: April 30th 2008, 03:40 PM
  3. Change repeating decimal to fraction
    Posted in the Pre-Calculus Forum
    Replies: 6
    Last Post: December 5th 2007, 08:34 PM
  4. Decimal into a fraction
    Posted in the Math Topics Forum
    Replies: 5
    Last Post: September 29th 2007, 11:26 PM
  5. fraction for decimal
    Posted in the Algebra Forum
    Replies: 1
    Last Post: March 12th 2007, 01:39 PM

Search Tags


/mathhelpforum @mathhelpforum