What is 13.217142714271427142... as a Fraction?

13.217142 equals 13215821999900 as a fraction.

How do you turn 13.217142 repeating into a fraction?

Detailed Answer:

Step 1: To convert 13.217142 repeating into a fraction, begin writing this simple equation:

n = 13.217142 (equation 1)

Step 2: Notice that there are 4 digits in the repeating block (7142) and 2 digits in the non-repeating part (21). Multiply both sides by 10⁶ = 1000000.

1000000 × n = 13217142.7142 (equation 2)

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

1000000 × n = 13217142.7142
    100 × n = 13.217142
 999900 × n = 13215821

n = 13215821999900 (answer)

13.217142 = 13215821999900 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 13215821999900 is also equal to 13217121999900 when expressed as a mixed number.

The repeating decimal 13.217142 (vinculum notation) has a repeated block length of 4. It is also represented as 13.21714271427142... (ellipsis notation) which equals approximately 13.2171427142714271427142 (decimal approximation)(*).

The recurring decimal 13.217142 can be written as a ratio of two integers having 13215821 as the numerator and 999900 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.