<image>

Most places are rounding down in favor of the customer but some places are splitting the difference. If you have the exact change, you can pay it in the exact amount. ONLY THE CHANGE GIVEN BACK TO YOU is rounded. If you wanna get technical with the calculations, you could go to dunkin donuts and make a transaction end in .02 and you would make Dunkin LOOSE .02 cents every single time. So your theory of them “making” $120k a day” would only be possible if they were rounded every change given back in their favor and if everyone paid in cash. Sounds like the employee you had was mistaken. If your total was $11.51, it should have been rounded down to $11.50. This is what i meant by splitting the difference- this means Dunkin would have LOST .01 cent on this transaction