In the history of science , abacus was first made around 190 A .D. at the end of the Eastern Han Dynasty . In the “Supplementary Records of Arithmetic” written by Xu Yue at the time , it was stated , “Calculation by abacus is applied in all times and in all respects .”

　　The Chinese abacus was a means of graphic arithmetic , based on graphic signs . The predecessor of the abacus is the arithmetic sticks . An ancient arithmetic stick was a regular three of four inch long bamboo stick . By arranging a number of arithmetic sticks graphically , an arithmetic operation was carried out . The arithmetic sticks not only could be used for addition and subtraction , but could also be used for multiplication and division . In the Spring-Autumn Warring States period , the multiplication table was already learned widely among the population . In the Yuan-Ming Dynasties , too many arithmetic sticks were used in business activities , and the graphs of them could be unclear and cause errors .
　　A ceramic model ship in the Eastern Han Dynasty was unearthed in ceramic modern ship in the Eastern Han Dynasty was unearthed in Guangzhou . An axial rudder was found at its stern . It was transitional from the long oar rudder to the axial turning rudder . Between the second and fourth centuries A.D. , the true axial turning rudder was used already in China , which was important for raising ship-operating efficiency . In about the twelfth century A.D. both the water-tight compartments and the axial turning rudder spread westward to the Mediterranean via the Indian Ocean . In the eleventh century A. D. the Chinese already invented the balance rudder and the holed rudder , both of which were only found in Europe at the eighteenth century A.D.

　　So abacus was made to replace the arithmetic sticks . The operation on a Chinese abacus was convenient and simple , and was used to work out complex multiplications , divisions , square roots and cubic roots , leading the rest of the world . The Arabian and Greek abacus could only be used to work out additions and subtractions . The Roman abacus that used the twelfth index system was the first to be eliminated . Only the Chinese abacus is easy to use and is still widely used in China , Japan and many other parts of the world . In fact , the Chinese abacus has inspired the invention of the mechanical computer . “Abacus is the simplest computer that demands operational programs.” (“The History of Development of Computers”) The Chinese abacus shed light on the inventions of various computers .