We here at Void are often asked many calculator-related questions such as "how do I put <whatever> on my calc", "what is a shell", or "how come I can't get <something> to work". Most of the time, answers to these questions can be found in several other places, number one being your calculator's manual, but for your convenience we have linked to them here.
Please take the time to search through these FAQs before coming directly to us with a question. Thanks!