What is 2.12857857857... as a Fraction?

2.12857 equals 4252919980 as a fraction.

How do you turn 2.12857 repeating into a fraction?

Detailed Answer:

Step 1: To convert 2.12857 repeating into a fraction, begin writing this simple equation:

n = 2.12857 (equation 1)

Step 2: Notice that there are 3 digits in the repeating block (857) and 2 digits in the non-repeating part (12). Multiply both sides by 10⁵ = 100000.

100000 × n = 212857.857 (equation 2)

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

100000 × n = 212857.857
   100 × n = 2.12857
 99900 × n = 212645

21264599900 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 = 21264599900 = 212645 ÷ 599900 ÷ 5 = 4252919980. So,

2.12857 = 4252919980 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 4252919980 is also equal to 2256919980 when expressed as a mixed number.

The repeating decimal 2.12857 (vinculum notation) has a repeated block length of 3. It is also represented as 2.12857857857... (ellipsis notation) which equals approximately 2.12857857857857857 (decimal approximation)(*).

The recurring decimal 2.12857 can be written as a ratio of two integers having 42529 as the numerator and 19980 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.