How do you calculate logarithms on TI-30X IIS?

To calculate logarithms on a TI-30X IIS calculator, press the "LOG" button for base 10 logarithms or the "LN" button for natural logarithms (base e). Enter the number you want to find the logarithm of, and then press the "=" button to get the result. For logarithms of other bases, use the change of base formula: log_b(a) = log(a) / log(b), where you calculate the logarithm of 'a' and 'b' using the LOG button.