This thread reminds me of a pet peeve of mine - people who can't use their own bloody calculators. They buy a decent Casio Graphical (or TI whatever) and then spend almost zero time learning to use it. There is a lot of power and quite a bit of borderline cheating you can do with the thing if only you learn how to use it. There are certainly a lot of ways of verifying calculations you have to show by hand in the exam that in moments can identify where/if you have gone wrong.
I prefer my HP50g but I cannot use that in A level because of the CAS on it - so I bought a Casio fx9860-gII - but I made sure I put a lot of time into learning how to use it - amazing how many do not.