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	$212.55	11.190%	$236.3343	$236.33	$236.35	$236.30
Purchase #2	$7.32	3.264%	$7.5589	$7.56	$7.55	$7.60
Purchase #3	$231.72	4.587%	$242.349	$242.35	$242.35	$242.30
Purchase #4	$190.65	4.133%	$198.5296	$198.53	$198.55	$198.50
Purchase #5	$20.31	11.736%	$22.6936	$22.69	$22.70	$22.70
Purchase #6	$238.58	8.249%	$258.2605	$258.26	$258.25	$258.30
Purchase #7	$184.99	6.364%	$196.7628	$196.76	$196.75	$196.80
7 purchase totals =	$1,086.12		$1,162.4887	$1,162.48	$1,162.50	$1,162.50