What is 87.8999... as a Fraction?

87.89 equals 87910 as a fraction.

How do you turn 87.89 repeating into a fraction?

Detailed Answer:

Step 1: To convert 87.89 repeating into a fraction, begin writing this simple equation:

n = 87.89 (equation 1)

Step 2: Notice that there is 1 digit in the repeating block (9) and 1 digit in the non-repeating part (8). Multiply both sides by 10² = 100.

100 × n = 8789.9 (equation 2)

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

100 × n = 8789.9
 10 × n = 87.89
 90 × n = 7911

791190 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 9 (the GCF - greatest common factor).

n = 791190 = 7911 ÷ 990 ÷ 9 = 87910. So,

87.89 = 87910 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 87910 is also equal to 87910 when expressed as a mixed number.

The repeating decimal 87.89 (vinculum notation) has a repeated block length of 1. It is also represented as 87.8999... (ellipsis notation) which equals approximately 87.899999 (decimal approximation)(*).

The recurring decimal 87.89 can be written as a ratio of two integers having 879 as the numerator and 10 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.