Anonymous
Anonymous asked in Science & MathematicsMathematics · 1 year ago

How do you convert from decimal form to fraction form?

I know the ones out of 100 but for example I got 4.5 for an answer but the answer key said 9/2 so I was wondering if there was a way to convert it to that.

11 Answers

Relevance
  • 1 year ago
    Favorite Answer

    Here's a way that will work for any terminating decimal.

    Write that as a number over 1.

    4.5

    ----

    1

    Now you want to move the decimal point to the right one place, but you have to do that as well in the denominator.

    45

    ---

    10

    Now you can reduce the fraction. Both the numerator and denominator have a common factor of 5, so divide both by 5.

    9

    --

    2

    You can't reduce any further, so that is the answer.

    4.5 = 9/2

    • Commenter avatarLogin to reply the answers
  • 1 year ago

    4.5=450/100=45/10

    • Commenter avatarLogin to reply the answers
  • Dixon
    Lv 7
    1 year ago

    The smallest decimal position is tenths (for the 5).

    So we have 45 tenths.

    45/10 . . . . . . . . cancel 5's

    = 9/2

    • Commenter avatarLogin to reply the answers
  • Jim
    Lv 7
    1 year ago

    You can multiply ANY number by (1)

    (10/10) = 1

    4.5 (10/10) = 45/10

    now reduce (remove factors of (1):

    45/10 = (5/5) 9/2

    so

    9/2

    ====

    OR another example, 0.005

    0.005 (1000/1000) = 5/1000

    This method works for any (nonrepeating) decimal.

    • Commenter avatarLogin to reply the answers
  • How do you think about the answers? You can sign in to vote the answer.
  • Bob L
    Lv 7
    1 year ago

    Start with 4.5 over 100, and find the least common deniminator between the two numbers. it would be 9/200, not 9/2. To get the decimaal to a whole number, it must be multiplied by 2 (4.5x2=9). But then, the denominator must also be multiplied by 2 (100x 2 =200). 4.5/100 = 9/200.

    • Commenter avatarLogin to reply the answers
  • sepia
    Lv 7
    1 year ago

    4.5

    = 4 1/2

    = 9/2

    • Commenter avatarLogin to reply the answers
  • Mike G
    Lv 7
    1 year ago

    4.5 = 45/10 = 9/2

    • Commenter avatarLogin to reply the answers
  • 4.5 = x

    10 * 4.5 = 10 * x

    45 = 10x

    45/10 = x

    4.5 = x

    45/10 = x

    4.5 = 45/10

    45/10 =>

    (5 * 9) / (5 * 2) =>

    9/2

    • Commenter avatarLogin to reply the answers
  • 1 year ago

    Re-imagine your number as a fraction: 4.5/1

    What would it take to make that a clean fraction? Aha! 4.5 is half of 9! To get there you'd double the numerator but you'll also have to double the denominator to match. So,

    "Multiply by 1": 4.5 / 1 x 2 / 2 = 9 / 2

    Okay, we got that out of the way. Now see if you can do the original problem without the calculator. :)

    • Commenter avatarLogin to reply the answers
  • 1 year ago

    4.5 with ".5" means it is some odd number of halves

    4.5 = x/2

    x = 2 * 4.5 = 9

    4.5 = 9/2 as an improper fraction

    • Commenter avatarLogin to reply the answers
Still have questions? Get your answers by asking now.