Any district board may confer upon any administrator the authority to suspend a pupil from a teacher’s class or from the school not in excess of ten days for any one offense and for not more than thirty days in any one school year but no such administrator may suspend a pupil from school during the last ten days of a year if the suspension will make the pupil ineligible to receive credit for the school year without the approval of the school board unless the presence of the pupil constitutes an actual threat to a class or a school or a hearing is granted within twenty-four hours of the suspension.