This seems to vary with dialect. In AmE the most common way to express a value like 0.80 (adding addition precision to your example) is with the actual word "zero" for 0 and "point" for the decimal point:
It is also acceptable to leave out the zero to the left of the decimal:
Also, the final zero only matters if you care about that degree of precision. This will vary with context, and not necessarily whether the discussion is professional or scientific. Sometimes it matter, sometimes it doesn't. If not, then you can say:
It is not uncommon even in some professional contexts to use "oh" in place of "zero", but only for the numbers to the right of the decimal.
Our heading is two-one-point-oh-five degrees, north by north east. (21.05 NNE)
The magnitude of the explosion was three-point-oh-five times ten-to-the-thirteenth power joules. (3.05 x 10^13)
As the other answer mentions, some (British) dialects prefer "naught" to "zero". Possibly also Ireland, Canada, Australia, New Zealand, South Africa and other English-speaking countries. Some Americans will understand this, but many won't (until it's explained to them).