What do the keys on the TI calculator mean?

The keys on a TI calculator serve various functions, typically categorized into numeric, operational, and function keys. Numeric keys (0-9) input numbers, while operational keys (+, -, ×, ÷) perform basic arithmetic operations. Function keys (like sin, cos, tan, and others) access specific mathematical functions or modes. Additionally, some keys may provide access to graphing features, statistical calculations, or programming options, depending on the model.