What is 12.125714257142571425714257142... as a Fraction?

12.1257142 equals 12125593999990 as a fraction.

How do you turn 12.1257142 repeating into a fraction?

Detailed Answer:

Step 1: To convert 12.1257142 repeating into a fraction, begin writing this simple equation:

n = 12.1257142 (equation 1)

Step 2: Notice that there are 5 digits in the repeating block (57142) and 2 digits in the non-repeating part (12). Multiply both sides by 10⁷ = 10000000.

10000000 × n = 121257142.57142 (equation 2)

Step 3: Now subtract equation 1 from equation 2 to cancel the repeating block (or repetend) out.

10000000 × n = 121257142.57142
     100 × n = 12.1257142
 9999900 × n = 121255930

1212559309999900 could be the answer, but it still can be put in the simplest form, i.e., reduced.

To simplify this fraction, divide the numerator and denominator by 10 (the GCF - greatest common factor).

n = 1212559309999900 = 121255930 ÷ 109999900 ÷ 10 = 12125593999990. So,

12.1257142 = 12125593999990 as the lowest possible fraction.

As the numerator is greater than the denominator, we have an improper fraction, so we can also express it as a mixed number, thus 12125593999990 is also equal to 12125713999990 when expressed as a mixed number.

The repeating decimal 12.1257142 (vinculum notation) has a repeated block length of 5. It is also represented as 12.12571425714257142... (ellipsis notation) which equals approximately 12.125714257142571425714257142 (decimal approximation)(*).

The recurring decimal 12.1257142 can be written as a ratio of two integers having 12125593 as the numerator and 999990 as the denominator. So, it is a rational number (named after ratio). It can be shown that a number is rational if its decimal representation is repeating or terminating.

(*) At present, there is no single universally accepted notation or phrasing for repeating decimals.