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	$91.93	3.404%	$95.0593	$95.06	$95.05	$95.10
Purchase #2	$214.60	8.804%	$233.4934	$233.49	$233.50	$233.50
Purchase #3	$63.40	13.414%	$71.9045	$71.90	$71.90	$71.90
Purchase #4	$195.98	6.163%	$208.0582	$208.06	$208.05	$208.10
Purchase #5	$190.46	12.677%	$214.6046	$214.60	$214.60	$214.60
Purchase #6	$32.29	13.626%	$36.6898	$36.69	$36.70	$36.70
Purchase #7	$203.85	10.577%	$225.4112	$225.41	$225.40	$225.40
7 purchase totals =	$992.51		$1,085.2210	$1,085.21	$1,085.20	$1,085.30