Positional notation
Positional notation or place-value notation is a method of representing or encoding numbers. Positional notation is distinguished from other notations (such as Roman numerals) for its use of the same ...
Positional notation - Wikipedia
Decimal representation
A decimal representation of a non-negative real number r is an expression in the form of a series, traditionally written as a sumwhere a0 is a nonnegative integer, and a1, a2, … are integers satisfyi...
0.999...
In mathematics, the repeating decimal 0.999... (sometimes written with more or fewer 9s before the final ellipsis, for example as 0.9..., or in a variety of other variants such as 0.9, 0.(9), or ) den...
0.999... - Wikipedia
Repeating decimal
A repeating or recurring decimal is a way of representing rational numbers in base 10 arithmetic. The decimal representation of a number is said to be repeating if it becomes periodic (repeating its v...