5PM How Do You Do That Math So Fast?

Customer: How much is a sheeet of 100 24-cent stamps?
Clerk: $24.00.
Customer: Okay, I'll take a sheet.
Clerk: I don't have a sheet of 100. Will a roll of 100 be okay?
Customer: I don't know. How much is that?
Clerk: $24.00.

US Post Office
Newton, Kansas