I heard a native American read 0.18% (actually it was an interest rate) “zero point eighteen percent”. I know it should be “zero point one eight percent” or “eighteen hundredth percent”. “zero point eighteen” might be not a standard way to say, however, do natives say that way? The website below says so, but I’m not sure.
Sure, it’s fine.
If I were to say “zero point eighteen percent” I would be sure to clearly enunciate the word point to avoid confusion with 18% by the listener.
I personally would say “zero point one eight percent”, but then I say the book title as “Fahrenheit four five one”.
I learned in school (math class not English) that you NEVER EVER EVER say “point eighteen”. I had multiple math teachers say this. We would have been immediately corrected if we said “point eighteen”.
When stated as a fraction, then it is “eighteen hundredths”. As a decimal you would say “point one eight”.
There has been a growing tendency to use it as a number since, at least, 1998. Their contention is that when you say ‘point’ the idea becomes clear whether or not you mention it digit-wise or as a whole number. That’s logical!
Nowadays, people live faster than ever before! - as if they have to do more than what they can think of. And, the concept of saving TIME, SPACE and ENERGY is another aspect responsible for this change.