| 
                 
                  One day, the teacher inquired Peter: How much is four minus four?  Peter was tongue-tied. 
 the teacher got angry and said: What a fool! You see, if I put four coins in your pocket, but there is a hole in your pocket and all of them leak out, now what is left in your pocket? 
 
 The hole, replied Peter. 
 
 
 
 
 
 |