How about splitting a bill at dinner? Or contributing to a campaign on the go before it sells out?
1. Divide food bill between number of attendees
2. Divide drinks bill between number of drinkers
3. Each individual adds 1 + 2 and ponies-up accordingly
Apologies if I have misunderstood.
Add up what you ordered, write name of card you are using to pay on the back with the amount. Pass the check to the next person.