HP Prime or HP 50g

[Joe Horn]

(07-11-2018 10:33 AM)Voldemar Wrote:  I like these two [Home and CAS] separated modes on HP Prime. Easy to switch between the modes. Easier than it is on HP 50g if you need to switch between approx and exact.

Yes, one keystroke is easier than one shifted keystroke (RS+ENTER), but not by much.

JDW: WHY Home and CAS are separated on Prime follows from WHAT their intended uses are. Sometimes you just want to crunch approximate numbers like all the pre-HP28C calculators do (and the 49/50 in Approx mode), with a maximum of 10 or 12 significant digits input and output being more than sufficient. That's what Home view is for. But other times you want to perform math on long, exact integers, or do symbolic math, or combine the two (like the 49/50g in Exact mode). That's what CAS is for. They have to be separate modes so that the calculator knows what you want when you type a variable (evaluate it or use it symbolically) and when you type numbers (quickly and efficiently use as a rounded-off approximation, or go to the extra effort of keeping all the digits throughout all the calculations). Each mode is optimized for its intended purpose.