The Impact Mentoring Academy at the old Berkeley school celebrated International Pi Day on Monday at exactly 1.59 in the afternoon.

Why? The date and time matched the first numbers of pi — 3.14159.

Impact Mentoring Academy hosted a number of activities for their students, including:

• learning pi facts, the ratio of a circle’s circumference to its diameter

• pie-baking and eating

• ten-segment spinner with prizes if it landed on 3, 1, 4, 5 or 9

• prize awarded for reciting pi to at least nine digits

• prize for the person who could recite the longest value of pi

• Three pi demonstrator, a robot measuring perimeter

•RPi demonstration.

Pi Day is celebrated on March 14 (3/14) around the world. Pi (Greek letter p) is the symbol used in maths to represent a constant — the ratio of the circumference of a circle to its diameter — which is approximately 3.14159.

Pi has been calculated to more than one trillion digits beyond its decimal point. As an irrational and transcendental number, it will continue infinitely without repetition or pattern.

Pi’s infinite nature makes it a fun challenge to memorise.

Learn About pi

Pi (p) is the ratio of a circle’s circumference to its diameter. Pi is a constant number, meaning that for all circles of any size, it will be the same.

The diameter of a circle is the distance from edge to edge, measuring straight through the centre. The circumference of a circle is the distance around.

History of pi

By measuring circular objects, it has always turned out that a circle is a little more than three times its width around.

In the Old Testament of the Bible (1 Kings 7:23), a circular pool is referred to as being 30 cubits around and 10 cubits across. The mathematician Archimedes used polygons with many sides to approximate circles and determined that pi was approximately 22/7.

The symbol was first used in 1706 by William Jones. A ‘p’ was chosen for ‘perimeter’ of circles and the use of p became popular after it was adopted by the Swiss mathematician Leonhard Euler in 1737.

In recent years, Pi has been calculated to more than one trillion digits past its decimal.

Only 39 digits past the decimal are needed to accurately calculate the spherical volume of our entire universe.

• For more information about Pi Day visit www.piday.org/