A first grade teacher asks one of his pupils: "Brian, do you already know how to count?

Brian answers "Sure I do, my father taught me".

The teacher, who fails to believe little Bobby, decided to test the little guy. "OK, he continues Brian... what comes after two?" The teacher asks

"Three!" Brian instantly called out.

"Excellent" the teacher said, "OK, Brian, now, what comes after Five?"

"Six!" Brian said straight away

"Brian, I must say that your father is an outstanding teacher. I bet he is very proud of you"

"Oh, yes, he is" Brian replied

"OK, now for the last test"; the teacher said "What comes after ten?"

Bobby replied, without hesitating for a second "Jack"