The board may provide for the sale of any such bonds upon such terms and conditions as the board in its discretion may determine at public sale. Bonds may be sold by the board below the par or face value thereof, at a discount not to exceed 6 percent of par value; provided further, that in the case of refunding bonds the board may provide for the refunding being made, in whole or in part, by the exchange of such refunding bonds for the bonds to be refunded. Before selling the bonds, or any part thereof, the board shall give notice not less than 10 days prior to the date of sale by publication in a newspaper of general circulation circulating in the district inviting

sealed bids in such manner as the board shall prescribe. If satisfactory bids are received, the bonds offered for sale shall be awarded to the highest responsible bidder. If no bids are received, or if the board determines that the bids received are not satisfactory as to price or responsibility of the bidders, the board may reject all bids received, if any, and either readvertise or sell the bonds at private sale.