Happy Pi Day. In some countries the calendar dates are written with the month first. So the 14th day of March is written as 3/14. Just for fun, this day is now celebrated all around the world as PI day as the first few digits of pi are 3.14.

There are now so many sites that help you celebrate this event with your students. Pi is the mathematical tern for the relationship between the diameter and the circumference of a circle. The diameter fits around the circumference more than 3 times. This relationship is the same no matter what size circle you create. It is a number that never ends. But it is also a number where absolutely no pattern has ever been discovered. Humans find this astounding. They can’t believe that a number can exist without a pattern attached. They keep searching for one.

This relationship known in the times of the ancient Babylonians and Egyptians. The symbol π was first used to denote the circumference-to-diameter ratio in 1706 by Welsh mathematician William Jones. But it didn’t catch on until Swiss mathematician Leonhard Euler adopted its use in the 1730s.

In 2016, a Swiss scientist, Peter Trueb, used a computer with 24 hard drives and a program called y-cruncher to calculate pi to more than 22 trillion digits — the current world record for the enumeration of pi. If you read one digit every second, it would take you just under 700 000 years to recite all those digits.

March 14 is also Albert Einstein’s birthday. And physicist Stephen Hawking, considered by some to be Einstein’s intellectual successor, died on March 14 2018.

What can you do to celebrate PI DAY with your primary students?