.999999999999999999... Equal to 1?

They say:

"0.999… is the same as 1. Not just very close, but precisely identical:

a = 0.999…
10a = 9.999…
10a - a = 9.999… - 0.999…
9a = 9
a = 1

There's no trick here. It's just a mathematical fact that most people find deeply counterintuitive."


But doesn't 9a equal 8.99999999999999?