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	$173.67	13.279%	$196.7316	$196.73	$196.75	$196.70
Purchase #2	$184.48	8.120%	$199.4598	$199.46	$199.45	$199.50
Purchase #3	$90.79	6.345%	$96.5506	$96.55	$96.55	$96.60
Purchase #4	$131.76	12.494%	$148.2221	$148.22	$148.20	$148.20
Purchase #5	$200.68	5.587%	$211.892	$211.89	$211.90	$211.90
Purchase #6	$103.41	12.629%	$116.4696	$116.47	$116.45	$116.50
Purchase #7	$201.54	7.441%	$216.5366	$216.54	$216.55	$216.50
7 purchase totals =	$1,086.33		$1,185.8623	$1,185.86	$1,185.85	$1,185.90