Teacher: “If I gave you 2 cats and another 2 cats and another 2, how many will you have?”
Johnny: “Seven.”
Teacher: “No, listen carefully… If I gave you 2 cats, and another 2 cats and another 2, how many will you have?”
Johnny: “Seven.”
Teacher: “Let me put it to you differently. If I gave you 2 apples, and another 2 apples and another 2, how many would you have?”
Johnny: “Six.”
Teacher: “Good. Now if I gave you 2 cats, and another 2 cats and another 2, how many would you have?”
Johnny: “Seven!”
Teacher: “Johnny, where in the heck do you get seven from?!”
Johnny: Because I’ve already got a cat!”