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	$61.44	5.563%	$64.8579	$64.86	$64.85	$64.90
Purchase #2	$30.61	5.397%	$32.262	$32.26	$32.25	$32.30
Purchase #3	$107.74	3.354%	$111.3536	$111.35	$111.35	$111.40
Purchase #4	$24.76	12.611%	$27.8825	$27.88	$27.90	$27.90
Purchase #5	$57.57	4.501%	$60.1612	$60.16	$60.15	$60.20
Purchase #6	$193.71	5.393%	$204.1568	$204.16	$204.15	$204.20
Purchase #7	$225.78	12.134%	$253.1761	$253.18	$253.20	$253.20
7 purchase totals =	$701.61		$753.8501	$753.85	$753.85	$754.10