<i>If the customer has the pennies, they can use them. Payments with debit or credit cards, or cheques, can also be to the penny. But if the customer is paying cash and doesn't have the pennies, the total will go up or down to the nearest nickel. For example, $1.02 will become $1 and $1.03 will be $1.05.</i><p>Something just feels wrong about rounding. The customer would always get screwed. They should solve this problem by using the federal sales tax to round up/down. $1.25 + 5% = 5¢ of tax instead of 6.25¢.<p>That said, it would make sense for merchants to round down for cash purchases. It would be a tiny incentive to use cash rather than credit cards (which cost the merchant 2-4%)