On First Street and all streets and avenues running parallel therewith, the numbering, whether going east or west, shall begin at Main Street with “100” on the north side of such streets and avenues, and with “101” on the south side thereof, and at the next street or avenue parallel with Main Street the numbering shall begin with “200” on the north side and with “201” on the south side of such streets running east and west, and so on, increasing the number by one hundred at each such street or avenue parallel with Main Street, with the even numbers and fractions thereof on the south side of such streets and avenues parallel with First Street, until all are numbered. (Prior code § 5-43).