What is Pi? It is the ratio of the circumference of a circle to its diameter and a number that has fascinated many for thousands of years  because the ratio stays the same whether you are measuring very tiny circles or very large.

Pi is 3.141592653… ad infinitum, which is why it boggles the mind and continues to intrigue. Pi’s decimals go on forever and they never repeat!

In 2015 the date corresponds to the first five digits of Pi, 3.14.15—a very special Pi Day! Join in the Pi Day fun. Check out some great books on both kinds of Pi/e.

For kids, I love Sir Cumference and the Dragon of Pi and Sir Cumference and the First Round Table both by Cindy Neuschwander.  Pi in the Sky and Bed Time Math are fun too. 

For adults, Pi: A Biography of the World’s Most Mysterious Number is sure to fascinate if you're really interested in Math. If  that's a bit too intense try the wonderfully clever Pi vs Pie Quiz by Brandon Echter on ScienceFriday.com. 

Using our electronic database, JSTOR,  I found a great article in the magazineTeaching Children Mathematics called "Special Pi Day Ahead." It includes an excellent history of both Pi and Pi Day. 

After reading up on Pi Day head out to celebrate Pi Day of the Century at the Museum of Mathematics here in NYC. Can you guess why they are opening at 9:26 am instead of the usual time?

All that intellectual stimulation making you hungry? Try Pies: Sweet and Savory, Pie Love or American Pie: My Search for the Perfect Pizza.

After a busy day of Pi celebrations you can tuck the kids into bed with the very sweet, (no pun intended!) How to Make a Cherry Pie and See the USA or How to Make an Apple Pie and See the World, both by Marjorie Priceman. 

Happy Pie Day!