While this calculator has some new and good features, I HATE that they changed all the old keys around.  I don't want to dork around figuring out the new key sequences and hunting for keys that no longer exist...like the SUM key.  Where is it?  The keyboard is too different from the old keyboard.  They should have kept the old and added new as required.  I get so sick of electronics folks moving all the furniture, just so they can feel clever.  It is disruptive and time consuming to constantly have to figure out stupid process issues about where keys are newly located instead of just being able to use all the familiar keys and learn the new ones or new extra functions.  Not impressed.  I just want a TI-30 scientific calculator with solar power, but those are now $99.  It's ridiculous.  This may be my last Texas Instruments calculator, and I've been a fan since 1979.  Seriously, BAD MOVE with the keyboard layout.