What is 18.1318181818... as a Fraction?

18.1318 equals 3989220 as a fraction.

How do you turn 18.1318 repeating into a fraction?

Detailed Answer:

Step 1: To convert 18.1318 repeating into a fraction, begin writing this simple equation:

n = 18.1318 (equation 1)

Step 2: Notice that there are 2 digits in the repeating block (18) and 2 digits in the non-repeating part (13). Multiply both sides by 10⁴ = 10000.

10000 × n = 181318.18 (equation 2)

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

10000 × n = 181318.18
  100 × n = 18.1318
 9900 × n = 179505

1795059900 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 45 (the GCF - greatest common factor).

n = 1795059900 = 179505 ÷ 459900 ÷ 45 = 3989220. So,

18.1318 = 3989220 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 3989220 is also equal to 1829220 when expressed as a mixed number.

The repeating decimal 18.1318 (vinculum notation) has a repeated block length of 2. It is also represented as 18.13181818... (ellipsis notation) which equals approximately 18.131818181818 (decimal approximation)(*).

The recurring decimal 18.1318 can be written as a ratio of two integers having 3989 as the numerator and 220 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.