Used instead of the = key, % interprets the final operation carried out in the current calculation as follows:
If the final operator is + or - show the result as a percentage of the final operand.
If the final operator is * give the right operand as a percentage of the left operand.
If the final operator is / give the left operand as a percentage of the right operand.
If the final operator is x^y give the left operand raised to the power of the (right operand / 100).
In all other cases the % key gives identical results to the = key.
45 / 55 % gives 81.81... (45 is 81.81.. percent of 55)
11 + 89 % gives 112.35.. (89 + 11 = 100, and 100 is 112.35 percent of 89)