Adding the .0 expresses your intent that it is a float. Expressing intent in the code is a form of documentation and makes the code easier to maintain; someone coming later can tell you meant it to be one way, vs it accidentally being that way. It's no different than adding parens around elements in a math formula when they're not needed; if the formula is complex enough, adding some parens to group things can make it clearer to the person reading it, even if it doesn't actually change the behavior.
