After the Board of Review has completed its review of the assessment roll, the Assessor shall prepare a tax roll, or a combined assessment and tax roll, to be known as the "City tax roll." Upon receiving the certification of the several amounts to be raised, assessed and charged upon the City tax roll, as provided in the preceding section, the Assessor shall proceed forthwith (1) to spread the amounts of the general ad valorem tax according to and in proportion to the several valuations set forth in said assessment roll, and (2) to place other assessments and charges upon the roll as are required and authorized by the Council. To avoid fractions in computations on any tax roll, the Assessor may add to the amount of the several taxes to be raised not more than the amount prescribed by law, which added amount, when collected, shall belong to the City.