I am reading a book called “The Magic of Math” by Arthur Benjamin. It is a book about the wonders and patterns of mathematics. I just started the book and am impressed. I learned this trick and showed it to my girlfriend’s daughters. They were amazed.

Now, I am going to show you. I will actually show you the math.

1. Think of a number from 20-100.
2. Take the digits of that number and add them together.
3. Subtract the new number from the one you chose.
4. Add the digits in you new number together.
5. The answer is 9.

The answer, if you do the math correctly will always be 9. Here’s an example.

1. I choose 33.
2. 3+3=6
3. 33-6-27
4. 2+7=…
5. …9

It’s a simple trick and it always works. Try it at dinner with your friends.

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