Mixed Fractions on the HP Prime

[smartin]

(01-11-2018 02:51 AM)Joe Horn Wrote:  

(01-10-2018 11:58 AM)smartin Wrote:  Ah yes. I guess what was throwing me was that I couldn’t do this entirely in the CAS.

You can do it entirely in CAS, and it's guaranteed to be correct, unlike the Home method shown above which is NOT guaranteed to be correct, and in fact will ALWAYS be wrong if the fractions have more than a few digits in them, or if you're in FIX 2 mode or similar. Just type propfrac(Ans) and your fraction answer will be converted into the desired mixed number. The first example below is yours. The second example below shows how CAS gets the correct answer, but if you try the Home method it gets it wrong, even in Standard display mode.



Only use the Home [a b/c] method if (1) you're in Standard display mode, and (2) the fraction only has a few digits in it (e.g. very simple homework problems!).

Thanks for the detailed explanation. I'm now just getting used to, and learning to appreciate, the virtues of having a separate HOME and CAS workspace. But, I do find it a bit unpleasant that this simple use case of mixed fraction arithmetic should require rather specific knowledge of how the two modes behave to get the correct answer. I can't help but imagine how a student might get confused by this. It seems to me an area which could be improved in the OS.