… These are the numbers that we know and use today. They are in fact, widely use by people all over the world and can be easily understood by one, regardless of the language that one speaks. However, this was not the case during the ancient times, where the ancient people of different civilizations write their numbers differently. For instance, the ancient Egyptians use represent the number 1,000 with a picture of a lotus flower, while the number 2,000 was symbolised by a picture of two lotus flowers growing out of a bush! These numbers were actually written in hieroglyphics, a type of writing system that we have already come across in the article on "the start of written records".

The Egyptian number system was based on counting in groups of ten. Why was this so? It is believed that men began to count in groups of ten using his ten fingers. For the Babylonians of ancient Mesopotamia, they not only counted in groups of ten too but also in groups of sixty. Counting in groups of sixty was mainly for economic purposes, where their principal units of weight and money were the mina, consisting of 60 shekels, and the talent, consisting of 60 mina. They also divided the year into 360 days (6 x 60), the time of one hour into 60 minutes and each minute into 60 seconds. (Isn't this similar to the way we measure time today?) All mathematical record was kept on clay tablets, which thus also archaeologists to day to study the number system in Mesopotamia.

The Greeks, however, were the first to develop a truly mathematical spirit. They were interested not only in the applications of mathematics but in its philosophical significance, which was in the case for Greek philosopher, Plato. The Greeks were able to use mathematical formulas to show how true a particular statement or idea was. Some Greeks, like Aristotle, involved themselves in the theoretical study of logic, the analysis of correct reasoning. Pythagoras, a Greek philosopher and mathematician born in about 580 B.C., was the one who invented the Pythagorean theorem, which relates the sides of a right triangle with their corresponding squares. (Have you learnt this in school yet?J) Despite their deep interest in various aspects of Mathematics, the ancient Greeks did not invent a complete number system.

So who were the ones who invented the number system that we use today? Surprisingly, it was the Greeks who did so, as one may have expected given their strong interest in Mathematics. This set of numbers (0, 1, 2, 3, 4, 5, 6, 7, 8, 9), which is known as the decimal system of numeration, which is also known as the Hindu-Arabic numeral system, actually originated in India some 1,500 years ago! This invention can indeed be termed as "one of India's greatest contribution to the world", since our lives have been made so much easier with this easily understandable symbols. Imagine if we had used the Egyptian way of recording numbers (that is, using pictographs), how many lotuses would we have to draw for every number that we record?!

A lotus flower.

Euclid's proof of the Pythagorean theorem was rendered into Arabic in AD 1258 by the Persian mathematician al-Tusi.