Here's an interesting math trivia trick to impress a friend, a group, or class. Tell the person (or class) to think of their birthday...and that you are going to guess it.
Birthday Math Trivia 

You can skip down to the next math trivia trick if you don't care to know why it works.
We'll explain how this works with some simple algebra.
Let M be the month number and D will be the day number. After the seven steps the expression for their calculation is:
5 (4 (5 M + 6 ) + 9 ) + D = 100 M + D + 165
So therefore, if you subtract off the 165, what will remain will be the month in hundreds plus the day! That's Pretty Cool Math Stuff!
Now that you've seen some birthday math trivia, here's a birthday math trick you'll probably enjoy.
Here's another math trick / trivia that involves your age. It's really simple to do.
Now what do you notice?
For example if you are 12, watch what happens:
12 x 7 = 84
1443 x 84 = 121212
Your age will repeat 3 times in a row!
Return from Interesting Math Trivia to Math Games Home