Missouri Revised Statutes Title XI. Education and Libraries § 177.171. Contracts for furnishing school supplies--bids required when

The board of education shall cause advertisements to be made under regulations that it provides for proposals for furnishing the supplies required in the schools and by the board. Every contract shall be awarded to the lowest responsible bidder complying with the terms of the letting; but the board shall have and reserve the right to reject any and all bids. The board may authorize the purchase of supplies not exceeding five thousand dollars in amount without letting of contract. The board shall make distribution of supplies through the agencies and in the manner that it deems proper. The board may contract for textbooks or school apparatus for such term of years as it deems proper.