Can you recommend a decent online or software calculator? I'm looking for an online or software calculator that can show me the history of items I typed in, much like an expensive Ti calculator. 
Can you recommend any?

I recommend the free and open-source Sage software. Its a Computer Algebra System and a competitor to all the expensive over-the-counter CAS programs you can get. Fully functional.
You can also go to sagemath.com for an online hosted equivalent.
There is also Maxima, free for download. R and R-Studio are free also, if you are specifically gearing toward statistics. As well as Python and its numerous mathematical packages, also free.
If youre a student, you might get Matlab or Mathematica for free from your university, or at discount.  
