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内容概述数学竞赛中的有理数计算题,技巧性强,方法灵活.外形上,有时数值很大,有时项数很多,有时次数很高,有时运算方式很复杂;结构上,却常常蕴含某种规律.因此,计算时要在理解有理数的相关概念,掌握运算律和恒等变形公式的基础上,运用自己的机智,细观察、勤探索、找规律,计算与推理相结合,灵活巧妙地选择合理,简捷的方法解决问题.所以,此类题型的学习训练,对同学们的思维能力培养大有裨益.有理数的常用计算技巧主要有:拆项相消、错位相减、倒写相加、合理分组、字母化、凑整等.
Content Overview Mathematical competition in the calculation of rational numbers, skillful, flexible approach. Sometimes, on the appearance of a large number, sometimes a large number of items, sometimes a very high number, sometimes the operation is very complex; structure, but often contains some rules Therefore, the calculation must be based on the understanding of the rational concepts of rational numbers, master the operation law and the constant deformation formula, and use their own resourcefulness, detailed observation, diligent exploration, finding the law, combining calculation and reasoning, flexible and clever choice of reasonable ,Simple method to solve the problem. So, this kind of question-based learning and training is of great benefit to the cultivation of the students’ thinking ability. The commonly used computational skills of rational numbers are: deconstruction elimination, dislocation subtraction, and backward addition, Reasonable grouping, alphabetization, rounding, etc.