裂项相消法是数列求和的基本方法之一,是分解与组合思想在数列求和中的具体应用.通常把数列的通项拆成两项之差,在求和时大部分正、负项会相互抵消,于是前n项和就变成了首尾部分项之和.笔者近期通过学习、思考,发现裂项相消法的内涵和外延远远超乎想象,内容极其丰富多彩.现简单整理,与同学们共享. The fission item cancellation method is one of the basic methods of summation of sequences, and it is the concrete application of the decomposition and combination ideas in the summation of the sequence.Usually the general term of the series is split into two parts, most of them are positive, Negative items will cancel each other out, so the first n items and become the first part of the sum of the author recently through learning, thinking and found that the connotation and denotation of the fission cancellation law far beyond imagination, the content is extremely rich and colorful. Simple, share with classmates.