2+2+2=7
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 ***in ' cat at home!!!