The school board in every school district containing a city which has a population of not less than ten thousand inhabitants may:
(1) Employ the clerical help and telephone service which the board, in its judgment, deems necessary to administer the affairs of the public school system in the school district.
(2) Employ a business manager for the school district, at a salary to be fixed by the board for a term of not to exceed four years unless sooner removed for cause by the board, who shall, under the direction of the board, perform the duties delegated to him by the board relating to the business management of the school district. Under the direction of the board he shall have charge of the purchasing of all supplies and materials for the repair and maintenance of the school buildings and other buildings owned by the school district and the upkeep of all buildings and grounds of the school district. He shall, as far as possible, relieve the superintendent of schools of the business management of the school district, now delegated to superintendents of the school districts by school boards, so as to enable the superintendent to devote his full time to educational matters within the school district. The business manager shall at all times be subject to the direction and supervision of the school board in all duties he performs.