0.999… is the same number as 1. It’s counterintuitive, but mathematics says that it’s true. Whether you believe it or not is another matter.
I’m not even going to try to summarise all of the proofs and arguments for this result. The one I find most convincing is this:
x = 0.999…
10x = 9.999…
10x = 9 + x
9x = 9
x = 1
The main difficulty people have with this is the issue of whether a number could have more than one name. Usually I get people to first admit that 1/2 = 3/6 and that doesn’t bother them. Then 0 = -0. Then, in the decimal system, most numbers have a unique decimal expansion but the very rare weirdos A / 10^B have two, and it’s not a big deal.