Salary schedules may be reproduced for illustrative purposes; however in the event of a discrepancy or error, only the official salary schedule as adopted by the board of trustees and filed as the official minutes of board action shall be used for computation of salaries. Employees shall be paid a prorated salary based upon the actual number of days remaining in the official school calendar in the event the employee does not work the total number of days according to the official calendar. The Board of Trustees retains the right to set the compensation plan for the district according to their sole discretion