This calculator deserves zero stars, but that's not an option. Within an hour of using this calculator, the screen had 4 horizontal lines running across the entire screen, and within two weeks had about 20 of them. Did I mention that the calculator has only moved from a table to my hands and back, and has never been transported more than 3 feet? That's durability! Oh wait, that's sarcasm. I'd say within another week of use this calculator will be completely unusable. Tech support from Texas Instruments is worthless as well, as a replacement will take weeks. That's not really helpful when you're in the middle of a calculus class.
Worst purchase I've made on Amazon so far. This is complete garbage.