Where I am the correct answer would be kilometers
I'd say 'half a kilometre' but 'point 5 kilometers'
Sorry, Nick; I forgot to add both spellings.
This one is weird because saying "Point five kilomiter" sounds wrong because it's not a whole kilometer. But saying "Point five kilometers" sounds wrong because it's not multiple kilometers.
i live in america and we use miles, so it is .5 miles, but half a mile