The earliest calculation tool in China should be something called "suanchi". This tool appeared in the Spring and Autumn Period and the Warring States Period, but it is not known who invented it. The so-called "shuangchi" is simply a pile of small sticks of approximately the same length, and the material used for making them is mostly bamboo. The ancients would carry "calculating chips" with them and take them out for calculations when needed. It is currently unclear when this calculation tool appeared and who invented it. Relevant scholars speculate that the emergence of this calculation tool should be during the Spring and Autumn Period and the Warring States Period.
When using a tool such as a calculation chip to perform calculations, the ancients would arrange the sticks vertically or horizontally according to the size of the numbers required. The ones and hundreds digits are expressed in vertical format, and the tens and thousands digits are expressed in horizontal format. If they are zero, they will not be placed. In addition to using the "calculator" to perform addition and subtraction operations, the ancients could also use it to perform multiplication operations. In order to meet the calculation needs as much as possible, the ancients needed to carry more than two hundred "calculation chips" when going out. Therefore, in the subsequent development, "calculation chips" gradually began to evolve into directly engraving numbers on small sticks, thus improving the convenience of calculation.
Although this calculation tool is not very convenient, it was not gradually eliminated until the Ming Dynasty. The reason why "suanchi" was eliminated was the promotion of abacus. The calculation tool used in abacus is the well-known abacus. The invention of the abacus actually borrowed from the "abacus" to a certain extent, but it is still unclear when exactly it appeared. It is speculated that it may have appeared in the Eastern Han Dynasty, because the calculation method of abacus was mentioned in a book called "Shu Shu Ji Yi" during the Eastern Han Dynasty.
However, there are many scholars who hold different views on this. Some scholars believe that the abacus was invented in the Tang Dynasty, while others believe that the abacus only appeared in the Yuan Dynasty. Regardless of when the abacus appeared, it is certain that the calculation tool began to be used on a large scale during the Ming Dynasty, because abacus was mentioned in many ancient books of the Ming Dynasty. It is precisely because of this that "calculation plan" will be completely replaced.