For the whole "how many sweeps do you have to be to be an adult" thing, since 6 sweeps = 13 human years, that means that one sweep is 2.17 years. Since for us you become an adult at 18 years, then you probably become an adult troll at 9 sweeps since 8 x 2.17 = 17.36 but 9 x 2.17 = 19.53
I mean, instead of doing all that math LIKE A NERD, you could have just used the sweeps converter