I'm looking into my rune pages now that I have hit level 30, and there are a lot of decimal values for the runes, I want to know if those values round up or down while in game.
For example, for my AP page, I currently have 9 Greater Marks of Magic Penetration, giving me +0.87 Magic Pen each. This totals 7.8 Magic Pen (as shown to the right of the rune page)
In game, does the 7.8 round to 8? Does it round to 7? Or is there some wacky calculation for 0.8 Magic Pen?
If it doesn't round it seems like it would make sense to remove one of the runes, have 7 Magic Pen and have a single mark giving me something else, yet all the recommended builds I've found online always show having 9 of the same rune category.