Kaprekar's Constant D.R. Kaprekar was born on January 17, 1905 at a place called Dahanu, near Mumbai, in India. As a child calculations were his hobby. He would spend hours on end trying to solve maths puzzles and problems. As an adult he worked as a Mathematician and in 1946 he discovered the 'Kaprekar constant' - the number 6174. He died in 1988.

To work out Kaprekar's sort of "magic" you should:

   1.	Choose a four-digit number, for example, 5634.

   2.	Rearrange the digits in decreasing order, e.g. 6543.

   3.	Reverse the number obtained in Step 2, then subtract the smaller number from the larger one.

			  	  6543
				- 3456
			  	  3087

   4.	Take the number you have just calculated and repeat Steps 2 and 3.
 	This should be continued until the surprise hits you.

		  8730		  8532		  7641
		- 0378		- 2358		- 1467
		  8352		  6174		  6174

 Do you notice that with 6174 the process comes to a "stand-still"? That is, 6174 just repeats itself!

But the real surprise is yet to come.

If you try this again with any other four-digit number. It always ends with 6174. This is the famous Kaprekar's Constant.

   1.	Can you find the number that requires the most subtractions before you reach 6174?

   2.	What happens if the Kaprekar process is applied to three-digit or five-digit numbers?