In the days when an ice cream sundae cost much less, a 10-year old boy entered a hotel coffee shop and sat at a table. A waitress put a glass of water in front of him.
"How much is an ice cream sundae?" he asked. "Fifty cents," replied the waitress.
The little boy pulled his hand out of his pocket and studied the coins in it.
"Well, how much is a plain dish of ice cream?" he inquired.
By now more people were waiting for a table and the waitress was growing impatient.
"Thirty-five cents," she brusquely replied. The little boy again counted his coins. "I'll have the plain ice cream," he said.
The waitress brought the ice cream, put the bill on the table and walked away. The boy finished his ice cream, paid the cashier and left. When the waitress came back, she began to cry as she wiped down the table. There, placed neatly beside the empty dish, were two nickels and five pennies.
You see, he couldn't have the sundae, because he had to have enough left to leave her a tip.