1 = 0,99........

[Bridge]

It's totally irrelevant though. No computer is capable of computing infinitesimals so 1 - 0.9~ on any calculator will always be 1 x 10^-∞. Personally it makes my brain hurt so I have a hard time accepting it.

You calculate that with limits (needs advanced mathematics). A computer can calculate it with some mathematical methods. I cannot say the same for a calculator though. Well, like it or not, the proof is just above.

A calculator is a computer. I realize it is legit on paper but it is simply not practical. Almost all big calculations are handled by computers. You probably already know this, but there is no such thing as infinite memory. The number infinity has no calculable value and the value of 0.9~ requires an infinitesimal to precisely calculate and by definition computers need measurable data to calculate. Therefore neither of these operations are possible to truly calculate on computers. You always need to approximate, and with approximation comes a loss of data.

EDIT: I'm not saying I don't believe it, I just question its usefulness and whether or not the two numbers should be equal. When quantum computers become a reality we will most likely be able to precisely calculate the distance between 0.9~ and 1, because there is one, no matter how small, and the numbers will cease to be equal.