I get weird looks from the young folk in places where I'm not tapping the device with my phone to pay. And pay cash. Bought a drink once at a gas station convenience, handed the guy a $10. heard him say "Uh oh". Asked why and he said he punched in $20 rather than $10. I said not a problem, you just keep $10 of the change that comes up and it balances out. Told me he had to figure it out on his own since I "could be trying to cheat him". So he wrote down numbers, added/subtracted on his phone and finally came up with nearly $10 in change. So I got my drink for about 50 cents.... Basic math dude....