The most appropriate method for valuing small businesses is the multiplier method. This method uses an income figure, such as gross sales, gross sales and inventory, or net profit, and multiplies it by an appropriate coefficient to arrive at a value for the business. This type of estimate is best used as a very rough, preliminary valuation method because it ignores many important factors in determining the actual value of a company. Generally, valuing a company using the multiplier method requires annual sales (or revenues). Having a sense of the company's total asset value (including the value of all its current inventory and other holdings) and profit margins can also help in value estimation.  These values are typically available on a publicly-traded company's financial statements. However, for a private company, you will need permission to access this information. Sales or revenues, along with commissions and inventory expenses if there are any, are reported on a company's income statement. The coefficient used will vary based on the industry, the market conditions, and any special concerns within the business. This number is somewhat arbitrary in nature, but a good figure to use can be obtained from your trade association or from a business appraiser. A good example is BizStat's valuation "rules of thumb." The source of the coefficient will also specify the appropriate financial figures to use in your calculation. For example, total annual earnings (net income) is the common starting point. Once you find the financial figures needed and the appropriate coefficients, simply multiply the numbers to find a rough value for the company. Again, keep in mind that this is a very rough estimation of market value. For example, imagine that the appropriate multiplier for mid-sized accounting firms is estimated at 1.5 * annual revenues. If Anderson Enterprises' total revenues this year are $1,400,000, then the multiplier method yields a business value of (1.5 * 1,400,000) or $2,100,000.

TL;DR in Vietnamese:
Xác định đây có phải là phương pháp phù hợp để thực hiện hay không. Tìm số liệu tài chính cần thiết. Xác định hệ số thích hợp để sử dụng. Tính toán giá trị bằng hệ số.