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	$197.41	9.340%	$215.8481	$215.85	$215.85	$215.80
Purchase #2	$47.99	9.199%	$52.4046	$52.40	$52.40	$52.40
Purchase #3	$36.66	3.107%	$37.799	$37.80	$37.80	$37.80
Purchase #4	$232.94	5.849%	$246.5647	$246.56	$246.55	$246.60
Purchase #5	$172.65	13.614%	$196.1546	$196.15	$196.15	$196.20
Purchase #6	$214.72	4.297%	$223.9465	$223.95	$223.95	$223.90
Purchase #7	$95.84	8.167%	$103.6673	$103.67	$103.65	$103.70
7 purchase totals =	$998.21		$1,076.3848	$1,076.38	$1,076.35	$1,076.40