16. Unless otherwise provided, where the result of a calculation provided for in section 14 or 15 or in Schedule III is a decimal, the numbers appearing after the decimal point shall be dropped and, where the number immediately following the decimal point would have been higher than 4, the whole number shall be increased by 1.
Where section 14 or 15 or Schedule III provides that the number resulting from a calculation must comprise a certain number of decimal places, the last number after the decimal point shall be increased by 1 where the next number would have been greater than 4.