Question

it mean it is infinite 999999!!!​

Answer 1

This is significant because your approach to the problem is to say that since 1/9 is just a decimal point followed by an infinite number of zeroes, that when you multiply this infinitely repeating sequence by 9, you would get 0.999999999….

0.(9) or 0.9 with point above, is already reserved notation to denote “1.”

The same is for 0.99999… = 1. notation.

Objection!

But in a same time anyone could imagine a distinguishable number “left” or “right” from 1., introduce some notation to represent it. In

Answer 2

$\huge\mathcal{\fcolorbox{lime}{black}{\orange{❥Aɳʂɯҽɾ࿐}}}$

• In mathematics, 0.999... (also written as 0. 9, in repeating decimal notation) denotes the repeating decimal consisting of an unending sequence of 9s after the decimal point. ... The utilitarian preference for the terminating decimal representation contributes to the misconception that it is the only representation.