There are 246 math problems in Nine Chapters Arithmetic, which are divided into nine chapters. Its main contents are as follows: The first chapter is the calculation of the research field area of "square field"; The second chapter is "millet", which studies the conversion of grain-grain ratio; Chapter 3 "Decreasing scores" studies the problem of proportional distribution; The fourth chapter is "few but wide", where the area, volume, length of one side and diameter are known. Chapter 5 "Business Work", studying geotechnical engineering and volume calculation; The sixth chapter, "lose-lose", studies the reasonable allocation of taxes; Chapter seven is "insufficient profit", that is, the problem of dual management; Chapter 8 "Equation" studies the problem of linear equations; Chapter 9 "Pythagorean Theorem" is solved by Pythagorean Theorem.