According to this, the decimals are just dropped, not rounded. So technically its rounded down. For example. 373.9 just becomes 373. Ill keep looking for more reliable sources but so far all the ones I found says they are are just dropped. HF's answer here suggest that it would be rounded down as well.
More sources saying it rounds down.
>Uh-oh! There is a decimal, now what? Well, in Pokémon, multiplication with decimals simply is not done. So, we eliminate the decimal, and round down to 478. Just pretend the decimal is not there, and you have your stat number! Keep in mind that if an item or ability is in effect, they must be incorporated. More on this is in the Ability Modifier and Item Modifier sections.
-Smogon Article