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Pi Day

Ted Fitzgerald/MediaNews Group/Boston Herald via Getty Images

What is Pi Day and why do we celebrate the holiday?

  • Mar 14, 2025

Pi Day mates math with pizza, dessert

  • Mar 14, 2023
Shutterstock

The 3 burning questions about pizza, answered

  • Mar 14, 2022
Shutterstock

Indiana once tried to define pi as 3.2; the bill almost passed

  • Mar 14, 2022

LIST: Pi Day discounts and events in Bay Area

  • Mar 14, 2022

Grab a slice and explore the possibilities of pi

  • Mar 4, 2022

Pi Day: Recalling infinite digits and reveling in celebratory pies

  • Mar 15, 2019

Celebrating Pi Day at the Exploratorium

  • Mar 13, 2019

Latest Videos

1:39

Antioch girl shows off crazy Pi memory skills

  • Mar 15, 2022
5:26

Pi Day: The 3 burning questions about pizza, answered

  • Mar 14, 2022
0:51

Pi Day 2022: 3.14 discounts and events in Bay Area

  • Mar 14, 2022
5:14

'Super Science with Drew': Explore the infinite possibilities of pi in time for Pi Day

  • Mar 4, 2022
5:39

Celebrating pi day at the exploratorium

  • Mar 13, 2019
3:19

Exploratorium executive director explains why we celebrate Pi Day

  • Mar 15, 2018
1:25

Quirky Pi Day celebrates its 30th anniversary at the Exploratorium

  • Mar 14, 2018
1:18

How to measure pi using a real pie

  • Mar 14, 2018

Latest Stories

Stephen Curry to play in Under Armour low-tops for first time

Stephen Curry will play in low-tops for the first time since having his own Under Armour signature line of sneakers.

  • Mar 23, 2018

Stephen Curry debuts new Under Armour sneaker on 30th birthday

Though he'll miss Wednesday night's game against the Lakers, Stephen Curry is celebrating his 30th birthday by debuting his latest signature sneaker, the Curry 5.

  • Mar 15, 2018
KGO-TV

Exploratorium executive director explains why we celebrate Pi Day

Wednesday is Pi Day, where we celebrate the number 3.14, which stands for the circumference of any circle divided by its diameter.

  • Mar 15, 2018
© Exploratorium

Pi Day has San Francisco roots

In 2009, Congress designated March 14 as National Pi Day, but the celebration of the irrational number began much earlier. A physicist at San Francisco's Exploratorium dreamed up the celebration 32 years ago, in 1988.

  • Mar 14, 2018

VIDEO: How to measure pi using a real pie

Exploratorium scientist Julie Yu demonstrates how to measure pi using a string and real fruit pie.

  • Mar 14, 2018