March 14th (or 3/14 in some countries) is known as Pi Day around the world. To help you celebrate, you can find a whole host of brilliant Pi Day teaching resources here: Pi Day - 14th March
Pi - represented by Greek letter “π” - is the symbol used to represent a constant: the ratio of the circumference of a circle to its diameter — which is 3.14 to 3 significant figures but goes on forever! At the time of writing Pi has been calculated to over 50 trillion digits beyond its decimal point.
One simple way you can celebrate the day is to collect a whole host of circular objects (cup, glass, glue stick etc), a long piece of string and a ruler. Use the string and ruler to find the circular length around each of the object (the circumference), as well as the width of the circle part you are measuring (the diameter). If you divide the larger number by the smaller, you’re calculating C/d, which depending on the accuracy of your measurement, should always give you 3.141592…
Give it a go – how close did you get?
This activity is a great introduction to pi for many students, and they are often surprised by the result as a more common representation of this relationship is 
But that isn’t the only way to calculate pi. One way is with the following set up – known as the Monte Carlo method:
Imagine randomly dropping pins on to the diagram below, a circle with radius of 1 within a square:
As the radius is 1, the area of the circle is πr2 = π and the area of the square is (2r)2 = 4. The ratio of dots inside divided by the total number of dots is 
. So, divide the dots inside by the total number of dots, then multiply by four, and you should get pi!
Give it a go – did this method give you a better result?