ID does not allow you to use 0 as a logical page number (no idea why not), so if you need 1.0, 2.0, 3.0 etc, you're going to have to cheat in some way.
I'd do it by creating new sections for each ".0" page (so you'd have a section for the .0 and the next page would also start a new section with numbering reset to 1). For the .0 pages I would do two more things. First, instead of a section prefix, add the number you want for that section, 1.0, 2.0 ..., as a Section Marker. Now create a new master page to assign to these special pages and in place of the Current Page Number marker insert the Section Marker marker from the Insert Special Character > Markers menu.