Scientific American presents Math Dude by Quick & Dirty Tips. Scientific American and Quick & Dirty Tips are both Macmillan companies.

Do you know any good math puzzles? If so, please send me a note and let me know what they are—I'm always looking for good puzzles to add to my collection and to share with math fans around the world. If not, today we're going to take a look at 3 fun listener-inspired math puzzles that you can use to kick-off your collection and amaze your friends at future dinner parties.

Ready to be puzzled? And then un-puzzled? Good, because that's exactly what today is all about. Enjoy!

Puzzle 1: Think of a Number
Our first puzzle comes from math fan Kristina. She writes:

"Math Dude, can you help me explain how this works?? Think of a number. Add 3. Double the result. Subtract 4. Cut that number in half. Subtract the number you first thought of. Your answer is 1!"

> Continue reading on