Natural Logarithm. Pressing g LN calculates the natural logarithm of the number in the display; that is, the logarithm to the base e.
Natural Antilogarithm. Pressing e†x calculates the natural antilogarithm of the number in the display; that is, raises e to the power of that number.
Common Logarithm. Pressing g LOG calculates the common logarithm of the number in the display; that is, the logarithm to the base 10.
Common Antilogarithm. Pressing 10†x calculates the common antilogarithm of the number in the display.