Generally I use this calculator:
But I always bring the crappy clear calculator from the bookstore just in case the prof/TA is really picky (CHEM 121, 122). I suppose it is programmable, but I don't use those features--it's just the "standard" calculator the bookstore sells is really, really terrible.
On another note, is anyone willing to share good Celebration of Light parking lots? Normally I'd transit but I'm at school until 5:30 pm that day so I'd have to ditch the car at home first then transit out. Pay is fine (within reason), walking 30-60 minutes is fine.
Otherwise, has anyone ever had problems with leaving their car in B-lot late at night?