Not all percentages in EvE wont work the way they seem they do.
For example, if you have a base resistance of 60 and you have a mod that enhances that resistance with 25%, you wont get 85 (60 + 25) or 75 (60 * 125%) resistance, but 70!
So what is going on?
Figures in EvE kinda work the other way around of what you would think them to work.
So instead of taking 60 (in the above example) as the figure to work with, they take the 40 'UNresistance' and work from that. 40 unresistance - 25% = 30 unresistance, = 70 resistance.
This also works for the 'Connections' skill (add 4% to standing per level). Skill level V would add 20% to your standings, but again, it works the other way around. Standings can be seen as a number between 0 and 20, 20 being -10 (yeah, minus) and 0 being +10. Having connections at V, while at a base standing of -10 will give you an effective standing of -6 (20 - 20% = 14 -> standing = -6 (it works the other way around, remember? so the skill removes 'UNstanding' instead of adding standing).
This all means that percentages are most effective to stuff you have least of. The previously mentioned mod will give you 25% resist when the base resist is 0, but only 12,5% when your base resist is 50. Connections V will give you 4 standing points when you have a base standing of -10, but only 1 standing point when your base standing is 5.
Of course, using this system enables CCP to get around figures higher than intended (standing >10, resists >100%, etc), but on the other hand, it means you can't trust the description of some skills and mods.
(NOTE: this system not seem to apply to stuff like range, in fact, the above mentioned examples are the only 2 things I noticed this 'upside-down' approach on, but there may be more...)
