We're having a bit of a debate over in Aerospace Combat, so I wanted to ask here to see if there was any official word on this.
The rule in question is the fire control weight for WarShips that mount more than 20 guns in an arc.
To determine the weight of these systems, divide the number of weapons mounted in any firing arc that exceeds its weapon limits (12 for JumpShips, 20 for Space Stations and WarShips) by the limit value, and round the result down to the nearest whole number. Multiply this result by 0.1 times the total weight of all weapons mounted in that arc (discounting ammunition), and round the final result up to the nearest half. This is the final weight of any expanded fire control and power systems the unit requires for such weaponry.
I parse that as "Divide the number of weapons by the limit,
if it exceeds the limit". The other fellow in this debate parses it as "Divide the number of weapons
in excess of the limit by the limit". So for a ship with 25 guns in an arc, I'd divide 25 by 20 and go from there, while he would divide 5 by 20 and go from there.
I think I'm correct here, because I'm pretty sure that his method would result in no fire control weight at all until you had 40 guns, which is a very strange result if 20 is the limit. However, I can't be sure, so I submit it to your judgement.
(
Apologies if this is clarified in errata - my workplace blocks the hosting site that hosts the errata document, so I can't check it EDIT: I've checked now, it's not there.)