有理数的运算技巧性很强,特别是对某些竞赛题,直接计算十分繁琐,并且容易出错,若巧用“配对”思想,充分发挥配对后的联合效应,则可收到简捷求值的效果.现以竞赛题为例,介绍以下6种常用的配对方法. Rational arithmetic skills are very strong, especially for some competition titles, direct calculation is very tedious, and error-prone, if you use the “pairing” idea, give full play to the joint effect after pairing, you can receive the effect of simple and effective evaluation Here is an example of a competition. Introduce the following six commonly used pairing methods.