This one is probably a fairly old one, but I laughed reading it today, enjoy.
There once was a 5 year-old boy. His name was Little Timmy. At his age it is time for him to attend kindergarten school. But young Timmy didn’t want to go to school, and refused to his mother. In reply, little Timmy’s mom said, “I’ll tell you what. If you get straight A’s in your classes each marking period, I will give you whatever you want. Little Timmy, loving his bargain, went straight to school that morning.
That marking period, Little Timmy’s mother checked his grades. To her enjoyment, she found he had gotten all A’s. She then said to Little Timmy, “What do you want as your gift?” Now, Little Timmy thought a moment. He then said to his mother, “I want a Ping Pong ball.” Puzzled, Little Timmy’s mother agreed, and bought him a Ping Pong ball. The next marking period, Little Timmy had gotten A’s again. His mother asked him again, “What do you want as your gift?” Now, Little Timmy thought a moment. He then said to his mother, “I want 2 Ping Pong balls.” Puzzled still, Little Timmy’s mother agreed, and bought him 2 Ping Pong balls.