All is set for event to boost interest in math

March 09, 2010

All is set for event to boost interest in math

thecitizen.co.tz

By Beniel Seka

When you mention 'Pi-Day', many people may ask: What is it about? Who discovered it? What is its importance? Why set a special day for Pi?" and so on. By definition, 'pi' (pronounced as 'pai') is the ratio of the circumference of a circle to its diameter. In other words, it is the circumference of a circle divided by its diameter. 'Pi' is always the same number, no matter which circle you use to compute it.Mathematicians call such a number a constant. 'Pi' is a constant you can easily find practically. Try it and you will find that it is one of the most interesting activities to do.

Just take a circular object, measure the length of the distance around the object (circumference) and the distance from one end to the opposite end through the centre (diameter). Then divide the circumference by the diameter. Do this for various objects. If you do it accurately you will note that the ratio is close to 3.14 when you round it to two decimal places.

Pi is approximately 3.14 when taken to two decimal places. Pi-Day has been created from this value of pi. Pi-Day is on the 14th of March. Three (3) is used to represent the third calendar month (March) and 14 represents the 14th day.For many practical cases, you can use 3.14 but if you want a better approximation you can use a computer to get it. The approximation to 5 decimal places is 3.14159. Mathematicians who created Pi-Day also suggested 15th of March to be 'Little Pi-Day' because number 15 follows 14 immediately in that order.

It certainly seems knowing the value of pi to four decimal places suits most people's everyday needs. However, some mathematicians are not satisfied with that. For example, William Shanks, a British mathematician, spent 20 years doing calculations by hand and obtained the value of pi to 707 decimal places.

He published his results in 1873. Sadly, he had made an error in the 528th decimal place, which went on undetected until 1945. In 1948, John W French Jr and D.F.Ferguson published pi to 808 decimal places. You should now have noticed that pi is an infinite decimal. Unlike numbers such as 5, 2.6 and1.56, which have finitely many nonzero numbers to the right of the decimal place, pi has infinitely many numbers to the right of the decimal point. 

The numbers to the right never repeat in a pattern. However, although many mathematicians have tried to find a pattern, no repeating pattern has been discovered to date. In fact in 1768, Johann Lambert proved that there could not be any such repeating pattern.Historically, pi is a very old number. We know that the Egyptians and the Babylonians knew about the existence of the constant ratio pi, although they did not know its value nearly as well as we know it today. 

They had figured out that it was a little bigger than 3. Even the legendary Archimedes knew and used pi in his geometrical work. He is said to have estimated pi by the rational number 22 divided by 7. 

The modern symbol for pi is (-), which looks like a cross section of a small stool. The symbol was used for the first time by William Jones in 1706. 

Pi (rather than some other Greek letter like alpha or omega) was chosen as the letter to represent the number 3.141592… because the letter (-) in Greek stands for 'perimeter'. Many people recognise the symbol because it has been taught in schools from primary level to higher institutions of learning such as universities. Many people still recall the formula for calculating the area of a circle, "pi r squired." But how many people go beyond the formula? 

How to derive the formula is a simple activity that you can perform. It is left for you as an exercise. You will find it quite enjoyable. Ask a veteran to give you a hint or read any mathematics book containing the activity and you will make it. You are now ready to celebrate Pi Day.The celebration has been planned to take place on 15th March (Little Pi Day} since 14th March is on Sunday. The celebration will begin with a charity walk from Kenton High School to the Tanzania Institute of Education grounds.

The activity is expected to be led by a trumpets group and escorted along the roads by traffic police.There will be a lot of singing, dancing and appeal for support of stakeholders to help efforts to promote children's interest in mathematics. Join them in making the celebration a success.

Mr Beniel Seka is a freelance writer. He can be contacted on: 0784498893 or E-mail: sekabeniel@yahoo.com or sekabeniel@gmail.com