The physical calculator allows students to use this calculator in the classroom. If a student was using a smartphone on a test, how does the teacher know at cheating is not going on?

That said, this calculator does allow a no-estimation-necessary mode, but entering that mode causes some LEDs along the top to blink. If the student thinks he or she can get away with it while the teacher is looking away, those LEDs actually keep flashing for a while after switching back to estimate-first mode.

I think it's a good idea! The calculator's ease of use is stopping people from thinking about what a correct answer should look like.