I have setup a webform to take registrations and payments for events. I have enabled tax to be 10% and have calculated the cost of each event to be 10% less, so Civi will add on the tax to each line item (i assume that this is the only way Civi Tax works). The total is $0.1 by out. Here is why:
$75 - 10% = $68.18 (I have set the Participant Fee to $68.18)
$68.18 * 3 events = 204.54 Add the tax: 204.54 * 0.1 = 20.454 ($20.45, rounded)
$20.45 + 204.54 = $224.99
Are these patches still relevant?