Do you know that 14 March is celebrated as Pi Day? No, this Pi here is not Pie the delicious dish. Pi is the mathematical constant pi (π). Pi Day is observed on 14 March (3/14 in the month/day date format) since 3, 1, and 4 are the first three significant digits of π.

π is originally defined as the ratio of a circle’s circumference to its diameter. Its decimal representation never ends and never settles into a permanent repeating pattern. Because π is closely related to the circle, it is found in many formula from the fields of geometry and trigonometry, particularly those concerning circles, spheres, or ellipses. Other branches of science, such as statistics, physics, Fourier analysis, and number theory, also include π in some of their important formula.

Remarkably, Pi Day is celebrated by eating and throwing pies, very much the same with Pie Day celebration! It is because the words “pi” and “pie” being homophones in English (/paɪ/). Pi Day is also celebrated by discussing the significance of the number π, or by memorizing the value of π with precision. You could even join the search for the next decimal digit of π. The latest record was held in 2016 by Peter Trueb by finding the 22,459,157,718,361th digit!

14 March is also celebrated as Einstein’s birthday. Albert Einstein, who was born on 14 March 1879, was a German-born theoretical physicist. He was famous for developing the theory of relativity, and his well-known mass-energy equivalence formula is E=mc². In 1921 Einstein received the Nobel Prize in Physics. During his life, Einstein had published more than 300 scientific papers along with over 150 non-scientific works. His intellectual achievements and originality have made the word “Einstein” synonymous with “genius”.

Einstein’s Day celebration is usually combined with Pi Day celebration. In addition to Pi Day’s activity, there will be Einstein look-alike contest. Pi Day and Einstein’s Day could also be celebrated by watching math-inspired movies or holding math-inspired quizzes with families and friends!

If you have not been a math lover, then Pi Day and Einstein’s Day is the perfect day to start to get to know the incredible field of study! So how about you? Tell us your favorite Pi Day and Einstein’s Day activity, or share your most memorable Pi Day and Einstein’s Day celebration!