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	$195.98	11.165%	$217.8612	$217.86	$217.85	$217.90
Purchase #2	$64.55	12.472%	$72.6007	$72.60	$72.60	$72.60
Purchase #3	$156.58	8.175%	$169.3804	$169.38	$169.40	$169.40
Purchase #4	$12.31	13.328%	$13.9507	$13.95	$13.95	$14.00
Purchase #5	$180.89	10.373%	$199.6537	$199.65	$199.65	$199.70
Purchase #6	$158.83	8.729%	$172.6943	$172.69	$172.70	$172.70
Purchase #7	$140.65	12.244%	$157.8712	$157.87	$157.85	$157.90
7 purchase totals =	$909.79		$1,004.0122	$1,004.00	$1,004.00	$1,004.20