About this specific case: I also never knew using ".5" to mean "0.5" is a thing, until I lived in the US.
Not sure if it's a US thing or Western world thing, my country (not Japan, but also in East Asia) just doesn't use it.
Not sure if it's a US thing or Western world thing, my country (not Japan, but also in East Asia) just doesn't use it.
I don't press the zero button on my calculator when inputting values, though, since it's an extra keystroke for literally nothing.
"Set the power to point three" sounds the same orally as "Set the power two point three"
The zero makes it unambiguous.
Except in deliberate word-by-word pronunciation, "one two three" and "one to three" sound different in native US English.
I've never seen 0.5 written ".5" going back to Principia.
(Things are rarely drafted according to specs.)
Without a decimal it will strip leading zeros by default, a setting that has caused me hours of frustration over the years.