Development of Mathematics in Ancient China
By the time of the Han Dynasty (2nd Century B.C. to 4th Century A.D.), the Shang numerals were developed into a system and used on a counting board and a set of counting-rods (chousuan). Chinese computational methods were based on many mechanical aids, or early computers, including a large variety of counting boards. Indeed, the evolution and development of counting rod numerals continued for about 3000 years in China, from 14 century BC. to 13th century AD.
The abacus is perhaps the best known counting board, but it was only developed around the 15th century. Counting boards were divided into columns designating positional groupings of 10. Zero was indicated by a blank space on the counting board, and negative numbers were also used in mathematical calculations. Two types of rods were used, red and black or positive and negative, representing Yin and Yang.
Before the dawn of the Christian
era, over 2,000 years ago, the Chinese were solving systems of
equations with a method similar to the modern transformations of
matricies. Tangrams and other aids were also invented in China
during the Chou dynasty. In addition, over the thousands of years
of mathematical progress, the Chinese have invented a large
variety, and countless numbers, of mathematical puzzles and
games. 
The linear units of measure were as follows:
1 chang = 10 ch'ih
1 pu (pace) = 5 ch'ih
1 ch'ih (foot) = 10 ts'un (inch)
