specific-question This question was recently discussed on meta: Stein-Shakarchi Real Analysis Ch1 Ex2(a): representation of elements in the Cantor set.

It is related to ternary expansion of real numbers. I wanted to add tag related to this. Which tag should be used for questions related to binary, ternary, ... expansions of real numbers. Is number-systems a reasonable choice?

At least based on the tag-info it seems like close to this topic: "Representations of numeric values in decimal, binary, octal, hexadecimal, and other bases; one's-complement and two's-complement signed numbers; scientific notation; floating-point numbers in digital computers; history of number systems; nonstandard number systems; algorithms for arithmetic within specific number systems or for conversions between number systems."

I'll add that there is a separate tag decimal-expansion.