I am in the usher rotation at my church. Normally this entails wearing a suit or sportcoat, smiling, saying hello, offering bulletins, and occasionally scrambling when not enough people show up to take the collection. There are a few other things that I might have to do. I have first aid training, know CPR, and am familiar with where the church keeps the defibralator. I've even wondered what would happen if the church were to be attacked by ak-47 toting terrorists. I have never considered what would happen if someone were to need change for a $20 in the aisle during the offering.
It was almost a surreal event. An older man, very polite and devout but probably on a fixed income, couldn't afford to give all of the $20 in his wallet. My co-usher was thinking ahead and simply told him to keep it and talk to us after the service. Then we had to scramble in order to find someone who could actually make him change. The cash in the offering plates would be counted and in the church safe by the end of the service. The church administrator wasn't in, the pastors don't handle money, what do you do?
In the end what he wanted was $10 back. I had a ten in my wallet so that took care of things. I left the money in an envelope on the administrator's desk.