A first-grade teacher was having trouble with one of her students. 

One day she asked Johnny what his problem was he replied, “I’m too smart for the first grade. My sister is in the third grade, and I’m smarter than her too.”

The teacher took him to the principal’s office and explained the situation to the principal. The principal told her that he would give Johnny a test, and if he failed to answer one question, he would have to go back to the first grade and be quiet. The teacher and Johnny both agreed.

Principal: “What is 3 x 3?”

Johnny: “9.”

Principal: “6 x 6?”

Johnny: “36.”

And so it went on like this, the principal asked him every question a third grader should know. 

Finally, after about an hour, he told the teacher, “I see no reason Johnny can’t go to the third grade, he answered all of my questions right.”

The teacher asked if she could ask him some questions. The principal and Johnny agree.