Transcript:

Have you heard of Kaprekar's constant? No? So, if you have not heard of Kaprekar's constant, I won't give you the answer, but I'll tell you how you can arrive at it.

So start with any four-digit number with at least two distinct digits. Okay, so start with any four-digit number, at least two distinct digits.

Now, sort the digits from high to low. You get one four-digit number. Now sort the digits from low to high. You get the second four-digit number. Subtract them to get another four-digit number and continue doing this.

And eventually you will see that it converges to one constant number. That is Kaprekar's constant.

Okay, so do the math and write in the comments what you found. What is Kaprekar's constant?