Rounding of tax amounts to the nearest monetary unit applies; halves rounded up and smaller fractions ignored for dues and refunds. All amounts of tax, interest, penalty, fine or other sums payable, and all refunds or sums due under the Act, shall be rounded to the nearest rupee; where the fractional part of a rupee consists of paise, fifty paise or more is increased to one rupee and parts less than fifty paise are ignored.