Took multiple 'operator = Operator.RESET' lines out of calculate method() and just placed once after calculate() method is called (from evaluate() method)
Within evaluate method: added else statement that sets value to be the input if an operator has not been set.
Because value is of type fraction, I needed to amend how I set value to be the input.
Fraction Calculator now returns correct results for whole numbers. Next need to take care of fractions.