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	$167.59	4.615%	$175.3243	$175.32	$175.30	$175.30
Purchase #2	$17.26	13.133%	$19.5268	$19.53	$19.55	$19.50
Purchase #3	$169.31	4.401%	$176.7613	$176.76	$176.75	$176.80
Purchase #4	$107.83	4.721%	$112.9207	$112.92	$112.90	$112.90
Purchase #5	$201.93	4.406%	$210.827	$210.83	$210.85	$210.80
Purchase #6	$56.25	6.599%	$59.9619	$59.96	$59.95	$60.00
Purchase #7	$126.36	10.666%	$139.8376	$139.84	$139.85	$139.80
7 purchase totals =	$846.53		$895.1596	$895.16	$895.15	$895.10