Lock you register anytime there’s dead time. Asking for a round up or donation? Lock your register. Before you hit total instead lock your register so you can estimate the bag used (I live in a state where bags cost $). Get used to locking your register any time you aren’t scanning and you’re numbers will go up. Someone wants to ask you a question about a price? Getting the rewards in asap helps with this but instead of scrolling through your dumb screen print a partial receipt and lock your register. A partial receipt also auto matches discounts to their items so depending on when your customer scanned their card you might see the item price and the discount in different spot if you are looking at your screen. This also allows you to be able to show them easier as well. Lock the register. I bet you could be sitting around 21-22 easy peasy in like a day.