Little Johnny at it again !!
 

Teacher: If I gave you 2 cats and another 2 cats and another 2, how many will you have? Johnny: Seven, Sir.
Teacher: No, listen carefully... If I gave you 2 cats, and another 2 cats and another 2, how many will you have? Johnny: Seven, Sir.
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!!! SIR!
A very angry Teacher: Where in the hell do you get seven from?!?!? A very angry Johnny: Because,.... I've already got a f****** cat!!!