1. Choose any three-digit number (where the units and hundreds digits are not the same).

We will do it with you here by arbitrarily selecting 825.

2. Reverse the digits of this number you have selected.

We will continue here by reversing the digits of 825 to get 528.

3. Subtract the two numbers (naturally, the larger minus the smaller).

Our calculated difference is 825 − 528 = 297.

4. Once again, reverse the digits of this difference.

Reversing the digits of 297 we get the number 792.

5. Now, add your last two numbers.

We then add the last two numbers to get 297 + 792 = 1089.

Their result should be the same∗ as ours even though their starting numberswere different from ours.

They will probably be astonished that regardless of which numbers theyselected at the beginning, they got the same result as we did, 1,089.How does this happen? Is this a “freak property” of this number? Did wedo something devious in our calculations?

## About Bunchhieng

I like math, programming and web design!!