To be fair, there are a range of little issues when applying tax rates, not connected to the representation of the numbers involved. In Italy the generic VAT r

To be fair, there are a range of little issues when applying tax rates, not connected to the representation of the numbers involved. In Italy the generic VAT rate is 22%. When you expose a price (to the final customer) it is always included VAT, but VAT needs to be explicited on fiscal documents (receipt and/or invoices). So you have an article priced to the public Euro 2,69 (included 22% VAT), what is the net price and how much is the VAT? 2,69/1,22=2,204918... So, let's try rounding it to 2,20: 2,20x0,22=0,484=0,48 no, wait, 2,20+0,48=2,68 Ok, let's try rounding it to 2,21: 2,21x0,22=0,4862=0,49 no, wait, 2,21+0,49=2,70 You have to use the first and add 0,01 to the VAT to have it work: 2,20+(0,48+0,01)= 2,69