Section 9772 - Amount of tax to be collected(a) For the purpose of adding and collecting the tax imposed by this chapter, or an amount equal as nearly as possible or practicable to the average equivalent thereof, to be reimbursed to the vendor by the purchaser, the vendor shall multiply the total sales price of all the transactions taxable by the rate specified in section 9771 of this title carried to the third decimal place and rounded up to the nearest whole cent if the third decimal point is greater than four and rounded down to the nearest whole cent if the third decimal point is four or less. The tax may be computed on either the total invoice amount or on each taxable item.(b) The Commissioner may adopt transition rules that comply with any applicable multistate agreement in the event of a rate change.1969, No. 144, § 1, eff. 6/1/1969; amended 1971, No. 73, § 41, eff. 4/16/1971; 1981, No. 170 (Adj. Sess.), § 12; 1991, No. 32, § 10, eff. 6/1/1991; 1993, No. 1 (Sp. Sess.), § 2, eff. 9/1/1993; 2003, No. 68, § 32, eff. 6/18/2003; 2003, No. 68, § 62, eff. date, see note below; 2003, No. 152 (Adj. Sess.), § 19, eff. date, see note below; 2009 , No. 1 (Sp. Sess.), § H.42.