I suspect the sellers will all round up to the nearest nickel after tax is applied and end up making a little each person but a lot overall. Once the various governments see the potential to get more then tax rates will start adjusting to “make it simpler” also but more money for government and a few more cents for every purchase for us.
Places are already pricing by “rounding up.”
If you go onto sites like Reddit you will get a sense of how our schools have failed the youth. They “don’t get it.”
I remember being taught “rounding” in grammar school.