The division of two numbers is called the ratio of two numbers. The ratio is calculated by division, and the former item is divided by the latter item, such as 3: 5 = 3 ÷ 5 = 0.6. This 0.6 is the ratio of 3: 5, and the ratio can be expressed by a fraction, for example, 3: 5 = 3/5, and the ratio is three fifths. If the ratio of two numbers is not divisible, then the ratio is expressed by a fraction, and of course this fraction should be converted into the simplest fraction.