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	$186.27	5.732%	$196.947	$196.95	$196.95	$196.90
Purchase #2	$85.36	7.835%	$92.048	$92.05	$92.05	$92.00
Purchase #3	$108.83	9.219%	$118.863	$118.86	$118.85	$118.90
Purchase #4	$194.82	10.834%	$215.9268	$215.93	$215.95	$215.90
Purchase #5	$194.85	10.492%	$215.2937	$215.29	$215.30	$215.30
Purchase #6	$28.43	12.468%	$31.9747	$31.97	$31.95	$32.00
Purchase #7	$153.46	5.708%	$162.2195	$162.22	$162.20	$162.20
7 purchase totals =	$952.02		$1,033.2727	$1,033.27	$1,033.25	$1,033.20