A mid-range and programmable scientific calculator, the HP 11C has two features that are an improvement from an earlier version, the HP-33E/C. These two features are its built-in random number generator and a backspace key that enables users to correct a problem or formula one number at a time. Other built-in features of the HP 11C calculator include hyperbolic and inverse hyperbolic trigonometric functions, combinations and permutations on probability, percent change, factorial, and absolute value. The main advantage of the HP 11C calculator is its programming capabilities. This allows for label addressing (0-9 and A-E), subroutines (nestable to 4 deep), 8 conditional tests, increment/decrement loops, and 2 flags. Users also have the option to redefine the number of certain keyboard keys.