The dilemma

Forty six euros of food. The screen wants 4.60. The wine stopped the machine, so the trainee at the service desk came over, tapped her staff number in, and went back to folding bags. Her badge says MARINA, TRAINEE. Under the total there is a small grey line you did not see before: STAFF DISCOUNT 90 PERCENT APPLIED. She looks up from the bags, straight at your screen.

Your options

1. Tap pay and go. It rang up what it rang up, and a chain this size will never miss 4.60.
2. Wave Marina over and point at the grey line before you pay anything.
3. Cancel the sale and start again at the staffed till, where a person rings it up.