During the last Pi Day, the CRM served up a mathematical challenge addressed at students from the UAB Faculty of Science and Biosciences.
Every March 14th (3/14 in the month/day format) mathematicians and math enthusiasts all over the world celebrate Pi Day, named after the constant (known by the Greek letter “π”) that represents the ratio of a circle’s circumference to its diameter and its fascinating history. The date, which also commemorates Albert Einstein’s birth date and was the day Stephan Hawking died, was designated in 2019 by UNESCO as the International Day of Mathematics.
The day was first celebrated in 1988 at San Francisco’s Exploratorium, started by physicist Larry Shaw. Traditions for Pi Day include eating pie (pun very much intended due to the fact that “pi” and “pie” are homophones in English /paɪ/) and reciting from memory the decimals of the number π (if you want a crack at the record, the current Guinness World Record is held by Rajveer Meena of India, who, in 2015, recited 70.000 digits of Pi). This year the CRM joined the celebration with a mathematical challenge aimed at the student community here at the UAB Science and Biosciences Faculty, launched on the same day via the CRM’s social networks, with prizes for the first three people to bring us the correct solutions.
You go on a beach holiday, but you get bored and your mathematician friend helps you with a problem. She/He gives you two empty buckets, one with a capacity of 3/4 L of water and the other with a capacity of π / 4 L of water. He then asks you how you would end up with a bucket containing 1/4 L of water with an error of less than 1%? How many water transfers do you need to get what she/he has asked for?
Three students (two form mathematics and one from biology) got the solution right and claimed their reward.
In praise of Pi
Pi is an irrational number, which means that it cannot be represented as a fraction, and its digits go on forever with no recurring patterns. This means that Pi is infinite, and its exact value can never be calculated (an approximation such as 3.14 or 22/7 is often used for everyday calculations). Currently, about 62.8 million digits of Pi have been discovered, with a group of researchers from the University of Applied Sciences of the Grisons in Switzerland holding the record.
The Pi number has been known for almost 4.000 years, since the times of ancient civilizations such as the Egyptians and Babylonians. The first calculation of π was done by Archimedes of Syracuse (287–212 BC), one of the greatest mathematicians of the ancient world. Over the ensuing centuries, Chinese, Indian, and Arab mathematicians extended the number of decimal places known through tedious calculations, rather than improvements on Archimedes’ method. It was not until 1706, however, that the Greek π letter was used to identify the number, with Philologist William Jones first using the symbol. Later on, it was Leonhard Euler who popularized the use of the symbol among the scientific community in 1737.
Famous mathematicians such as Fibonacci, Newton, Leibniz, and Gauss, have worked on the number, calculating its digits and using it in numerous areas of mathematics.

CRM Comm Team
Anna Drou | Paula Lomascolo | Pau Varela
CRMComm@crm.cat
BMS-BGSMath Junior Meeting 2026: Barcelona and Berlin Strengthen Scientific Ties
From 2 to 4 September 2026, the Centre de Recerca Matemàtica (CRM) hosted the BMS-BGSMath Junior Meeting 2026, a three-day event jointly organised by the Berlin Mathematical School (BMS) and the Barcelona Graduate School of Mathematics (BGSMath), with the Centre de...
The CRM organises the 2026 Barcelona Summer School for Advanced Modeling of Behavior
The Centre de Recerca Matemàtica held the sixth edition of BAMB!, the Barcelona Summer School for Advanced Modeling of Behavior, from 12 to 23 July 2026 at the Parc de Recerca Biomèdica de Barcelona. Thirty early-career researchers from fourteen countries followed...
Mallorca’s 1820 plague did not behave like a classic bubonic outbreak, study finds
A study in PNAS by Pere Puig (UAB, CRM) and Joana Maria Pujadas-Mora (UOC, ICREA) reports what happens when the daily health records kept in Son Servera and Capdepera during the 1820 outbreak are analysed with a Bayesian epidemiological model: an unusually short...
A recent study quantifies the vegetable production potential of Barcelona’s rooftops
A study published in Cities by researchers at ICTA-UAB, with collaboration from the CRM's Knowledge Transfer Unit, estimates that 65 hectares of municipal rooftop could supply 31% of the tomatoes consumed in Barcelona each year.Barcelona has 65 hectares of rooftop...
CRM July Newsletter
CAVARET 2 brings together 83 researchers on curves and abelian varieties at the Universitat de Barcelona
The second edition of CAVARET, "Curves, Abelian VArieties and RElated Topics", took place at the Faculty of Mathematics and Computer Science of the Universitat de Barcelona from 13 to 17 July 2026. Sixteen invited lectures and ten posters brought together 83...





