For non-cash purchases, it doesn't matter, does it? I prefer cash when I can, for the record. If taxes add on, and pennies disappear, tax rules may change sinc

For non-cash purchases, it doesn't matter, does it? I prefer cash when I can, for the record. If taxes add on, and pennies disappear, tax rules may change since a few 100ths of a dollar may be required to round up from the total to be able to pay. Either those go to the shopkeeper (incentivizing them to set prices for the tax rounding behavior) or to the taxman.