Related Clues:

• Tip jar fillers, mostly
• Some vending machine inserts
• Bills not found in ATMs
• A small number
• Possible binary digits
• Change machine inserts
• Aces, at times
• Georges
• Not that many
• Column in an addition problem
• Rightmost column, perhaps
• Uno, un, eins, etc.
• Smallest greenbacks
• Some greenbacks
• You get five for a fiver