"Math Problems" joke

Young Larry stopped by the corner grocery store and read the following list to the clerk:

10 pounds sugar at $1. 25 a pound
4 pounds coffee at $1. 50 a pound
2 pounds butter at $1. 10 a pound
2 bars soap at $. 83 each

"How much does that come to?" asked Larry.

"Twenty-two dollars and thirty-six cents."

"If I gave you three ten dollar bills, how much change would I get?" said the boy.

"Seven dollars and sixty-four cents," stated the clerk who appeared to be irritated by all the questions.

Larry said, as he disappeared through the door, "I don`t want to buy the items... that`s our arithmetic lesson for tomorrow, and I needed some help with it."