Kinda depends on your programming experience I guess. I have a TI-89 graphing calculator here and I'm having some basic programming experiences about it (more on Inputs, Outputs, looping commands like For; While; If-Then; etc...), so I think the difficulty might be in the middle for me at least. And the prog language for those TI calculators is TI-BASIC, which isn't much different lol.

Yeah its not something you can really ask... Because I have Petit computer im still trying to learn... My advice is that its trial and error

I have a SmileBasic expert friend whom I can ask for help, but without him I'd rate a 6 in difficulty. There are certain parts I just won't get on my own and I can't deny spending hours getting frustrated over this. But that applies to academic studies too I guess.