If a number used in or resulting from a calculation made to determine the amount of an assessment under s. 126.15, 126.30, 126.46, or 126.60, other than a number that appears in one of those sections, extends more than 6 decimal places to the right of the decimal point, a person making the calculation shall round the number to the nearest whole digit in the 6th decimal place to the right of the decimal point. The amount of an assessment may be rounded to the nearest whole dollar.