There is a remarkable amount of disagreement as to whether one should do one’s back office work based on the price or based on the quantity of the counter currency.
> No one has .0000145 cents in their account. Rounding occurs in the real world.
Indeed. But you either need to convince all parties to agree to round the same way or you need to accept small errors
So, yes, everyone has to understand how all their partners are doing rounding and summing.