int calcFactor(int grade, void *factor) {
    return (grade * (*factor));
}

ex_3.c: In function `calcFactor':
ex_3.c:51:19: warning: dereferencing `void *' pointer [enabled by default]
  return (grade * (*factor));
                   ^
ex_3.c:51:2: error: void value not ignored as it ought to be
  return (grade * (*factor));
  ^