You may think that pi is an irrational number ... and on any given day, you'd be correct.

But on #NationalPiDay, pi is equal to pizza and pie deals. And we're here to help you celebrate.

According to, pi (π) is the ratio of a circle’s circumference to its diameter. Simply put, pi is comparing the distance around the outside of a circle to the distance across a circle from one edge to the other.

Here are some deals to take advantage of on #NationalPiDay:

Black Star Co-op will have pie specials all day

Little Woodrow's will serve up complimentary slices of pizza from Original Brooklyn Pie from 6 p.m. to 7 p.m. until supplies last for those who take part in "Bar Math"

Whole Foods is taking $3.14 off large bakery pies and large take-and-bake pizzas

Papa John's is offering two-topping large or pan pizzas for $9.99

Pizza Hut is charging $7.99 for two-topping pizzas for the month of March for online orders