I have sat for 5 CFA exams (just took level 3) and made the ultimate rookie mistake. I brought an unapproved calculator and did not even think about the calculator rule as I was practicing for the exam. Luckily, the person behind me let me use his spare calculator. I almost had a heart attack and could not get over the fact that, if I failed, it would be due to not having a calculator.
I later found my TI in my work bag.
I later found my TI in my work bag.