Kaprekar Constant 6174

This number was discovered for its magic by a school teacher, Mr. Kaprekar (1905-1986) of India:

1. Write any 4 digit number (the four numbers should not be the same digit). 
2. Reorder the digits to get the biggest number with those digits. 
3. Again reorder the digits to get the smallest number. 
4. Subtract 3 from 2
5. The new number - repeat steps 2 and 3.
6. Repeat step 4 for the new biggest and smallest numbers.
7. Within seven iterations, you will arrive at the Kaprekar Constant 6174! 

Here are five examples. go ahead, try it yourself!