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	$224.85	10.374%	$248.1759	$248.18	$248.20	$248.20
Purchase #2	$35.38	6.624%	$37.7236	$37.72	$37.70	$37.70
Purchase #3	$211.83	5.271%	$222.9956	$223.00	$223.00	$223.00
Purchase #4	$208.27	9.385%	$227.8161	$227.82	$227.80	$227.80
Purchase #5	$220.90	6.793%	$235.9057	$235.91	$235.90	$235.90
Purchase #6	$217.74	10.501%	$240.6049	$240.60	$240.60	$240.60
Purchase #7	$222.90	12.293%	$250.3011	$250.30	$250.30	$250.30
7 purchase totals =	$1,341.87		$1,463.5229	$1,463.53	$1,463.50	$1,463.50