A gaming system for playing a wagering game includes a controller configured to randomly generate an outcome of the wagering game and activate, for a winning outcome, a game feature responsive to an occurrence of a predetermined symbol along an activated payline. The controller randomly determines and displays a first operand and a second operand in an award modifier calculation and randomly determines and displays a mathematical operator to apply to the first and second operands. The controller applies the randomly determined mathematical operator to the first operand and the second operand to yield a modifier, modifies an award associated with the winning outcome using the modifier to yield a modified award, and awards the modified award.