There are few mathematical constants more well-known than pi, an endless number famous for frustrating school kids all over the world. Well, folks, it's Pi Day, and we're here to celebrate!

If you were looking for an excuse or occasion to make pie, mathematicians have invented one just for you.

On March 14, math aficionados celebrate Pi Day – the number that represents the ratio of a circle's circumference to its diameter.

Denoted by the Greek letter π, this peculiar number is generally referred to as approximately 3.14. This is rounded off, though, because the actual number is endless. In 2022, computers were able to calculate it to 100 trillion digits, but it is impossible to know the entire number.

This is why pi is so perplexing: it is an irrational number. The sequence 3.14159265358979323846… goes on for eternity, without following a single pattern – and never repeating itself.

Pi helps us calculate the vastness of space, explain how stripes and spots emerge in animal fur coats, and understand so much more about life.

On March 12, 2009, the US House of Representatives passed a bill recognizing Pi Day. Now, people honor Pi Day all over the world.

For example, the Jet Propulsion Laboratory holds a Pi Day Challenge, encouraging the public to solve math problems and think like scientists (give these previous tests a try). Various schools and organizations throw pi digit memorization contests.

The Massachusetts Institute of Technology honors Pi Day in a quirkier way. Every March 14, the university releases its decision letters to prospective students at 6:28 PM EST to honor tau, which is double the value of pi.

For food (and math) lovers, the pi-related discounts at US restaurants that sell circular food or offer endless pie-eating competitions might be sufficient to commemorate the holiday.

But if you were hoping to get into the kitchen and make pies from scratch, here are 3.14 recipes for the best pie to make on Pi Day:

Pumpkin Pi: You don't need to save pumpkin pie for Thanksgiving only. It is delicious all-year round. Check out our full recipe for pumpkin pie and enjoy it with every inch of your circumference.

Apple Pi: Who doesn't like a good apple pie? It's the perfect weekend dessert, topping off a lovely Sunday night roast or good ol' fashioned barbecue. With our beautiful apple pie recipe, you'll be pleasing the whole family as well.

Strawberry Forest Pi: A tart with jammy berries and a thick chocolate pudding layer is a draw for those who adore the flavors of traditional Black Forest gâteau. Its cold creamy texture provides a lightness to balance its intense flavors.

Creamy "Fruit Tart" Pi: If you prefer a mixture of fruits in your desserts, you might like a Creamy "Fruit Tart" Pie. Persimmons, plums, figs, and kiwis create a harmony of brightness and color.

It doesn't matter how big or small you choose to make your pies – the ratio, pi, stays the same. But maybe stick to the recipes' measurements for proper pie, rather than pi, success.