Exams are in a few weeks I don't have a huge amount of time to get used to a new format...
Hey, come on! You will be a commercial pilot in a couple of weeks. A little flexibility in adapting to changing technical environments is one of the pre-requisites of our profession. +, -, *, / and cosine is really all you need - you should be able to locate these five buttons on a different calculator in less than a day (maybe two if you want to fly for a low-cost airline
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BTW: Here in Germany the exams are "written" on PCs that run MS Windows. You are allowed to use the calculator application that comes with Windows during the exam and that's all what's ever needed.