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	$216.27	9.737%	$237.3282	$237.33	$237.35	$237.30
Purchase #2	$11.50	12.528%	$12.9407	$12.94	$12.95	$12.90
Purchase #3	$217.76	7.413%	$233.9025	$233.90	$233.90	$233.90
Purchase #4	$67.29	3.647%	$69.7441	$69.74	$69.75	$69.70
Purchase #5	$116.42	6.118%	$123.5426	$123.54	$123.55	$123.50
Purchase #6	$232.94	13.475%	$264.3287	$264.33	$264.35	$264.30
Purchase #7	$101.29	5.168%	$106.5247	$106.52	$106.50	$106.50
7 purchase totals =	$963.47		$1,048.3115	$1,048.30	$1,048.35	$1,048.10