It's National Pi Day, so treat yourself to some pie — pizza, dessert or both, whatever your heart desires! That first "Pi" ...

First Slice Pie Café in Chicago is offering a Pi Day deal at their Montrose, Manor and Andersonville locations. They’re offering slices of pie for $3.14, mini pies for $6.28 and whole pies for 20% ...

The number is known as 3.14 or π and can actually go on forever ... the highest number of Marco's Pizzas among states. Cici's Pizza customers who buy one medium or large 1-topping pizza ...

The proceeds will go to the Greater Chicago Food Depository. CiCi's is offering a $3.14 pizza for anyone who purchases one medium or large one-topping original round crust pizza with red sauce.