Pi Day, observed on March 14 (3.14), is here, and businesses are celebrating with the tastier pie.

Don’t forget pi is an infinite number that starts 3.14159. Pi is the ratio of a circle’s circumference to its diameter.

The holiday started in San Francisco in 1988; it’s apropos that the other pies being celebrated on Pi Day are round.

Here are the specials to check out Tuesday in the Las Vegas Valley.

Blaze Pizza

Address: Various locations

The California-based pizza chain is holding their “biggest pizza party of the year” nationwide for Blaze Rewards members.

Members can buy one 11-inch pizza at participating locations for $3.14.

The deal is only offered in restaurants.

Address: Vegas Test Kitchen, 1050 E. Fremont St.

Instead of needing to preorder from PopNpies, the small business will be selling pies by the slice from 11 a.m. to 5 p.m. at the Vegas Test Kitchen.

The restaurant hosts and rotates different businesses every day.

Cicis Pizza

Get $3.14 a large one topping pizza by ordering online for delivery or pickup with code “PIDAY.”

Customers can get up to 10 pizzas with this deal.

Crust & Roux

Address: 6825 Las Vegas Blvd. South, Suite 120 (Located in Town Square)

This gourmet pizza and pie restaurant is holding a bogo sale on all pizza pies, pot pies and dessert pies (of equal or lower price).

Customers can also get a free slice of pie with any non-pie purchase.

7-Eleven and Speedway

Address: Various addresses

7-Eleven rewards and Speedway rewards members can get a whole pizza for $3.14 on Pi Day.

Members can choose between the cheese, pepperoni and Extreme Meat pies. The Extreme Meat pie includes beef crumbles, pepperoni, bacon, Canadian bacon, Chicago-style sausage and diced ham.