What is 13.1428428428... as a Fraction?

13.1428 equals 1312979990 as a fraction.

How do you turn 13.1428 repeating into a fraction?

Detailed Answer:

Step 1: To convert 13.1428 repeating into a fraction, begin writing this simple equation:

n = 13.1428 (equation 1)

Step 2: Notice that there are 3 digits in the repeating block (428) and 1 digit in the non-repeating part (1). Multiply both sides by 10⁴ = 10000.

10000 × n = 131428.428 (equation 2)

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

10000 × n = 131428.428
   10 × n = 13.1428
 9990 × n = 131297

n = 1312979990 (answer)

13.1428 = 1312979990 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 1312979990 is also equal to 1314279990 when expressed as a mixed number.

The repeating decimal 13.1428 (vinculum notation) has a repeated block length of 3. It is also represented as 13.1428428428... (ellipsis notation) which equals approximately 13.1428428428428428 (decimal approximation)(*).

The recurring decimal 13.1428 can be written as a ratio of two integers having 131297 as the numerator and 9990 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.