Schools celebrate International Pi Day

It's Einstein's birthday and to celebrate, schoolchildren from across NSW are having a slice of pi.

You may know it simply as the end of the week, but Friday is in fact International Pi Day - 24 hours set aside to celebrate the famous number 3.1415926535 ad infinitum.

For those who didn't pay attention in maths class, it's the number you get when you divide the circumference of a circle by its diameter.

International Pi Day coincides with the birthday of German-born boffin Einstein and in Sydney, primary and secondary school pupils will gather at the Australian Museum to learn more about the number.

Aside from witnessing a Year Nine maths whiz reciting as many pi digits as he can remember, youngsters will also be encouraged to post Oscar-style selfies on Twitter, using the hashtag #PiDaySelfie.

"We know that students learn best if they enjoy what they are doing, so it is important to bring the fun element into mathematics," said Adjunct Professor Mike Clapper, director of the Australian Mathematic Trust.