对应法。大部分分数应用题的结构特点是一个具体量对应着一个分率 ，这种关系叫对应关系，找对应关系的思维方法叫对应法。运用对应法的关键是找出具体量 的对应分率。例1有一桶油，第一次取出25，第二次取出20千克，桶里还剩28千克 油，全桶油重多少千克?把全桶看作单位“1 Corresponding law. Most of the structural characteristics of the application questions is a specific volume corresponds to a fraction of this relationship is called the correspondence between the thinking method to find the corresponding relationship is called the corresponding law. The key to using the corresponding law is to find the corresponding rate of a specific quantity. Example 1  There is a barrel of oil, the first out of 25, the second removal of 20 kg, the barrel left 28 kg of oil, the whole barrel of oil how many kg? The whole barrel as a unit "1