This is handled by rounding. In the US many businesses already opt out of pennies and just round things down to the nearest 5 cents. It's just an extension of

This is handled by rounding. In the US many businesses already opt out of pennies and just round things down to the nearest 5 cents. It's just an extension of the rounding they already do (for instance when an 8.5% sales tax is added to a 1 dollar purchase, the half cent will be rounded even when the business uses the penny). Interesting historical note is that when the US half penny was removed from circulation due to it being nearly useless, it was worth approximately 8 cents in today's money.