What is 4.124285742857428574285742857... as a Fraction?

4.1242857 equals 82484891999980 as a fraction.

How do you turn 4.1242857 repeating into a fraction?

Detailed Answer:

Step 1: To convert 4.1242857 repeating into a fraction, begin writing this simple equation:

n = 4.1242857 (equation 1)

Step 2: Notice that there are 5 digits in the repeating block (42857) and 2 digits in the non-repeating part (12). Multiply both sides by 10⁷ = 10000000.

10000000 × n = 41242857.42857 (equation 2)

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

10000000 × n = 41242857.42857
     100 × n = 4.1242857
 9999900 × n = 41242445

412424459999900 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 5 (the GCF - greatest common factor).

n = 412424459999900 = 41242445 ÷ 59999900 ÷ 5 = 82484891999980. So,

4.1242857 = 82484891999980 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 82484891999980 is also equal to 42485691999980 when expressed as a mixed number.

The repeating decimal 4.1242857 (vinculum notation) has a repeated block length of 5. It is also represented as 4.12428574285742857... (ellipsis notation) which equals approximately 4.124285742857428574285742857 (decimal approximation)(*).

The recurring decimal 4.1242857 can be written as a ratio of two integers having 8248489 as the numerator and 1999980 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.