Funny that 1 litre is singular but 1.0 lires is plural even though 1.0 is more precisely singular than 1.
IOW, English is screwy
I might just take it that the special case is more for the word 'one', not the value of one.
Or perhaps more for one of a discreet object, where the litre is considered as a single thing but 1.0 is implying a continuous measurement so it changes how we think of it?
It’s the same in German. Not for liter because the German Liter is also its plural form.
If you write it out as "one litre" vs. "one point zero litres" it becomes a little bit more consistent though.
1 feet long cable.
10 foot long pole.
I disagree 1.0 is more precise one than 1.
Both in speaking language, and in quite some programming languages "1" is assumed to be an integer, and "1.0" is assumed to be a number with one decimal (something akin to a float). And I'd say integer "1" is the most precise type of one.
If we are rounding numbers you are right though...
round_to_int(0.5000000 to 1.499999) -> 1
round_to_one_decimal(0.9500000 to 1.049999) -> 1.0