However you slice it, the annual March 14 celebration of the mathematical constant π (pi) has blossomed into an international phenomenon recognized by the U.S. Congress and designated by UNESCO as the International Day of Mathematics. It’s also an excellent opportunity to enjoy pie, which seems to evoke quite a bit of nostalgia from participants in Berkeley Lab’s first-ever Pi(e) Poll. Continue to read to learn about your colleagues’ favorites, see photos, and follow interesting links about Pi Day.

While there was no clear winner in our decidedly unscientific poll, apple, banana cream, cherry, key lime, and pumpkin pies all garnered the same number of responses. Berry, pecan, and strawberry pies are also clear favorites. Interesting outliers included savory ones such as pizza, mince pie, chicken pot pie, and even haggis (definitively not a pie). There was some debate among the Elements staff about whether cheesecake should be considered a pie. Click on the pi(e) chart to see the entries, and leave your comments and quell the controversy.

If you’re interested in how other organizations and news outlets celebrate Pi Day, follow the links below:

Exploratorium: Guide to Celebrating Pi (π) Day

10 Ways to Celebrate Pi Day with NASA on March 14

NASA Pi Day challenge serves up a mathematical marvel

The New York Times: Love Pi Day? You Can Thank San Francisco for That

NASA Jet Propulsion Laboratory Pi Day

Thanks to Berkeley Lab’s Rebecca Hartman-Baker, Morgan Faulkner, Curtis Gomez, Ryan Ly, and Ayla Quesada for submitting original photos: