A lot. The fifth edition was published on 20 19. Compared with the fourth edition, it has changed a lot, and comprehensively improved the requirements of mathematical foundation and mathematical modeling. In addition, the difficulty and depth of the fifth edition have also increased, covering more mathematical knowledge and skills. Compared with the fourth edition, the fifth edition adds more mathematical modeling examples, cultivates students' ability to solve practical problems, and deeply explains and discusses some important mathematical theories and applications.