how to calculate profit margin formula Edwards and bell's point of view displacement he market demand for the mobile, server and SSD product rapid growth, make the memory and flash memory maker Micron and achieved good quarterly results, that is a signal to markets want to continual change. 6. The accounting benefit is bound by the prudent principle. According to the principle of prudence, when there are a variety of accounting methods to choose from an economic business of an enterprise, it should choose a method that neither overestimates nor depreciates the benefits. Enterprises manipulate profits to achieve homogenization of profits, most of which adopt the method of overestimating earnings, and the subjective selection of the period of value-added. The evolution of human beings has been through the process of inorganic small molecule, organic small molecule, organic polymer, multi-molecular system, primitive life, low animal, high animal and so on. The value phenomenon is accompanied by the development of human beings, and it is important to understand the origin of value in order to understand the value in a comprehensive and profound way, and to eliminate the many controversies existing in the theoretical circle of value. Humans evolved from lower animals, and the value phenomenon is not born, nor is it produced overnight. It has its own origins and evolves with the evolution of human beings. If W on behalf of commodity value, k represents the cost, with p represents the profit, so, as the money into profit, the capitalist conditions of commodity value, namely, W = c + v + m = k + m, on further into W = k + p, i.e. goods value + profit into the cost price.