Chinese invented "arabic" number system

The retired National University of Singapore mathematics professor, Dr Lam Lay Yong, 66, has crushed the long-held belief that the Arabs and Indians invented the numeral system used today. In fact, they came up only with the written symbols, says Dr Lam, who believes the Chinese invented the numeral system and were adding, subtracting, multiplying and dividing at least 1,000 years before anyone else, with simple bamboo rods.

The universal system using the numbers one to nine - known as the Hindu-Arabic system - has its roots in the rod bundles used in China from as early as 475 BC. Merchants, scholars, monks and court officials carried these rods, which they whipped out and used like calculators, placing them on boards or on the ground.

By putting one to five rods in various positions, the ancient Chinese invented a notation such that with the knowledge of only nine signs, any number could be expressed. Zero, thought to have been invented by the Hindus of India sometime after 600 AD, was designated much earlier by the Chinese using an empty space among sticks showing other numbers.

The rods were readily available to foreigners. The system was picked up by traders and travelers on the Silk Road during the Tang Dynasty, between the 5th and 9th century. The earliest known text on arithmetic based on the current Hindu-Arabic numerical system was written by an Arab, Muhammad Musa al-Khwarizmi, in AD 825, but the earliest Chinese treatise on the rod numerals and procedures for multiplication and division - the sun zi suanjing - "Nine Chapters of the Mathematical Art" was written in China about the similar rod-based concept some 700 years earlier.

By the 13th Century, the Chinese were solving very advanced problems with the rods, including equations with four unknowns. By some reason the Chinese did not however transfer the rod numeral system into a written system, which would have been identical with the Hindu-Arabic numeral system used today. The death knell for the bundles of rods came in the 16th Century with the invention of the abacus, which cut calculation times but sacrificed complexity for rote-learned methods.

Because of this, step-by-step reasoning was lost, Ms Lam said. "When the rods fell into disuse, mathematicians lost the ability to calculate advanced equations and mathematics declined."

When Dr Lam compared the procedures in both, she found, to her astonishment, that they were identical. "They could not have developed the same systems by sheer coincidence". The research work has taken 30 years.

Ms Lam will be presented with one of the highest accolades in her field, the Kenneth O. May medal from the IHCM at a mathematics congress in Beijing in August 2002.