Let's do some math ..  Rounding examples of 7 random hypothetical purchases:
Case	Tag   Price	Sales   Tax %	Raw Total   Incl. Sales Tax	Rounded   to Penny	Rounded   to Nickel	Rounded   to Dime
Purchase #1	$59.52	4.230%	$62.0377	$62.04	$62.05	$62.00
Purchase #2	$12.46	11.773%	$13.9269	$13.93	$13.95	$13.90
Purchase #3	$94.52	10.583%	$104.5231	$104.52	$104.50	$104.50
Purchase #4	$243.89	7.129%	$261.2769	$261.28	$261.30	$261.30
Purchase #5	$150.28	11.144%	$167.0272	$167.03	$167.05	$167.00
Purchase #6	$181.35	4.824%	$190.0983	$190.10	$190.10	$190.10
Purchase #7	$156.49	5.184%	$164.6024	$164.60	$164.60	$164.60
7 purchase totals =	$898.51		$963.4925	$963.50	$963.55	$963.40