It's Nation Pi Day

NBC - Today is March 14th and that means it's National Pi Day - the annual celebration that mimics the first three digits of the mathematical constant pi, 3.14.

It's also a day you can get sweet and savory deals on a pie with an "e", we're talking pizza pies and baked pies, which both owe their existence to circles!

Whole Foods marks Pi Day with $3.14 off select bakery pies while supplies last.

Kroger and Publix also have deals on select pies.

At Boston Market, purchase one chicken pot pie and a drink and get a second pot-pie for free with a coupon.

And many pizza restaurants around the country will also be offering deals to celebrate Pi Day.

If you have forgotten what pi means from your days in math class, pi is the ratio of a circle's circumference to its diameter.