Guan Jiuzhang

This book is called "Guan Jiu Zhang". It is a historical fictional article, focusing on time travel, tactics, logic, and hard knowledge. The protagonist Shen Yian is a modern actuary and financial tycoon. After a deliberate fire, he held a copy of the Song Dynasty's "Nine Chapters on Arithmetic" and traveled to an imaginary world set in the Song Dynasty. After time travel, the whole story revolves around the intrigues and partisanship in the court. The protagonist travels to Ningguo County on Jiangnan East Road, where there are constant frictions on the border and small-scale battles and attacks. The protagonist is a master of arithmetic, and uses nine chapters of knowledge such as square fields, corn, and decay as his "golden finger." Respond to subsequent tax and bank cases, corruption cases, land surveying, battlefield data analysis, etc. Step by step into the center of power in the court.