In the residence district comprising all of the city outside of the business district, from the corner of each block next to its respective baseline, each twenty five feet (25') of frontage shall be given a number; except where lots vary from twenty five feet (25') in width such lots shall be numbered to conform to the size of the lot. Where two dwellings are located on the same lot, the second dwelling shall have the same number as the first dwelling with the number one-half (1/2) added. (1953 R.C.)