When more than one tract or lot belonging to the same person is for sale at the same time, in the same municipal corporation or township, a part of one of the tracts or lots shall be offered, first for the payment of the whole sum due from the owner on all the delinquent lands or lots. If no person bids off a part of the tract or lot for the sum required, the tract or lot shall then be offered to the highest bidder for cash, and if any amount yet remains due, or if no person bids for a part or all of one tract or lot, each of the other tracts or lots shall be offered in like manner until the required sum is realized. If no one bids upon a part or all of said tracts or lots separately, enough to pay the amount due, then the whole of the tracts and lots shall be offered together and sold to pay the taxes, penalty, interest and costs thereon. This section shall be construed directory in character and a failure to comply therewith shall not of itself invalidate any sale.

(RSMo 1939 § 11128, A.L. 1959 H.B. 106)