在些数学题的数量关系复杂又特殊,采用一般的解题方法很难作答.这时可采取一种把问题推向“极端”的策略,也就是考察取最大或最小值的情形,则有利于我们找到解题的途径.请看下面的例题.例1:有两个四位数的差为1998,我们把这样的两个四位数称为一个数对,如3210和1212;6158和4160 The relationship between the number of math problems is complex and special, and it is difficult to answer the question by using the general solution to the problem. In this case, we can adopt a strategy of pushing the question to the “extreme”, that is, examine the case of taking the maximum or minimum value Example 1: The difference between two four digits is 1998. We call such two four digits a pair, such as 3210 and 1212; 6158 and 4160