Attack boosting confuses me [duplicate]

My Scizor is currently running Technician but I don't know how it works. I've read about it on Serebii and it says that any moves with a base power of 60 or lower are given a 50% boost. My Scizor has the moves Bullet Punch, Aerial Ace, Fury Cutter and U-Turn and is holding a Choice Band. Bullet Punch has 40 power and STAB makes it 60. Does Technician still boost it? And would the boost be an added 20 power or 30? And if the power is added by 20-30, making Bullet Punch's power 80-90, would the Choice Band raise it to 120-135? And U-Turn's base power is 70 and since it's higher than 60, Technician doesn't work on it, but would STAB make it 105? And would Choice Band raise it to 140-152.5?