Every year mathematicians and pie-lovers come together to celebrate Pi Day and make terrible maths jokes.
Because the Americans write their dates in the month/day format, March 14 is written as 3/14, which are the first three digits of pi (3.14).
But not everyone is on board with this special day.
In fact some people prefer tau (t) – another circle constant representing the ratio between the circumference and radius of a circle. It equals 2 times pi, which is approximately 6.28.
Some mathematicians argue that tau makes life simpler because in a circle, pi represents the ratio between circumference and diameter, which can make calculations a little confusing. This is because most mathematical calculations use the radius (half the diameter) to describe circles.
Take for example, a pizza that’s been divided into eight pie-shaped slices. The angle at the tip of the sliced pizza would be pi/4 and not pi/8. Using tau makes this much simpler because the pizza angle now is simply t/8.
Mathematicians say it also makes trigonometry (the study of the angles and lines found in shapes such as triangles) calculations easier.
Tau gained a lot of attention in 2010 when author and educator Michael Hartl posted The Tau Manifesto.
Which is why some people are keen to celebrate Tau Day, which is on June 28 (6/28 – geddit?).
But tau or no tau, the world will always have some hardcore pi fans.
Maybe a scrummy dish named after tau might sway things in its favour.