例说“逆向思维”策略解题

逆向思维是数学教学中常用,并且很重要的一种解题策略.该策略从问题的反面入手,转化并简化问题的计算和证明.     

逆向思维解题例说

<正>逆向思维是一种发散思维,是在研究问题的过程中有意识地去做与正向思维方向完全不同的探索.若原命题为真,则其逆命题是否为真?顺推不行时能否考虑逆推?直接不能解决的问题能否考虑利用间接解法?解题时应突破思维定势,创造性地去发现解决问题     

逆向思维解题例说

培养学生逆向思维的能力，能使学生对问题的本质掌握得更清楚，本文举例说明在数学解题教学中，如何培养学生的逆向思维能力。     

逆向思维解题例说

心理学认为,每个思维都具有与它相反的思维过程,在中学数学教学中,不但要培养学生的正向思维能力,也要培养学生的逆向思维能力,现举数例如下: 例1若三个方程x~2 4ax 3-4a=0,x~2 (a-1)x a~2=0,x~2 2ax-2a=0,中至少有一个方程有实数解,试求a的范围。分析:若从正面考虑,可有一个、三个或三个方程有实根共七种可能,甚繁,若从反面(三个方程都无实根)考虑则只有一种可能。解:由判别式得,关于a的不等式组     

逆向思维解题例说

逆向思维是一种发散思维,是在研究问题的过程中有意识地去做与正向思维方向完全不同的探索．若原命题为真,则其逆命题是否为真？顺推不行时能否考虑逆推？直接不能解决的问题能否考虑利用间接解法？解题时应突破思维定势,创造性地去发现解决问题的方法．在实际的教学过程中应不失时机地培养学生的逆向思维能力．下面通过具体事例予以说明．     

逆向思维训练教学例说

逆向思维是相对于习惯性思维而言的一种反思维。在研究解决某一些问题时,顺推不行时可考虑逆推,探讨正面有困难时,可探讨其反面,培养学生进行这种逆向思维,对提高解题能力,养成良好的思维习惯及掌握辩证法都是非常有益的,下面笔者结合教学实践,谈自己的一     

例说学生逆向思维的培养

思维定式在数学学习中有它积极的一面,同时也具有消极因素的一面．本文通过6个例子浅谈在高三数学教学中如何突破思维定式和培养逆向思维．     

例说数学解题中的逆向思维

在学习或解题时,许多学生或老师往往习惯于从正面入手,而忽视从逆向思考.其实,对于某些数学问题,当采用常规方法从正面解决感到繁琐、困难时,若能逆向思维,往往能化难为易,出奇制胜.本文试图从以下几个方面介绍逆向思维的应用,教师可把这种思维方法渗透到教学中,以培养学生的逆     

论篮球战术思想

篮球战术思想既是对篮球具体技战术的概括与提炼，又是指导篮球比赛和实践时所用系统战术的自我提高与完善。在我国篮球战术研究相对滞后的情况下，全面梳理篮球战术思想，界定篮球战术思想的不同类别并展望篮球战术是想发展的态势，显得至关重要。     

试论小学数学教学中引导学生思维的策略

小学数学教学的基本任务是教师在传授知识的同时,要培养学生的思维能力,发展学生智力。教师在课堂 教学中要善于通过创设情境、巧设疑问、动手操作等关键环节,教会学生思维方法,发展学生思维。     

解决几何问题的思维策略

针对学生解决几何问题的基本过程，提出相应的思维策略。     

老子否定式思维的现代意义

现代性的发展经历着一种全球化的过程。在这一过程中,追求利益最大化的主观目的,既促使了民族历史向世界历史的转变,也引起了文化焦虑。无可否认的是,传统文化作为一种宝贵的资源,可以在一定程度上改变或减轻这种文化焦虑。通过对传统文化的重新阐释使其获得新生,是传统文化在社会转型期进行现代化转化和发展的必由之路。为此,本刊特约请陕西省社会科学基金项目“转型期中国传统文化的现代转化”(05C003Z)课题组成员,撰写了此组笔谈,希望有助于促进传统文化的研究。     

双语教学的意义和策略思考

双语教学作为提高外语教学水平的一种现实选择，反映了效率低下的外语教学与日益增长的外语学习需要之间的尖锐矛盾。实施双语教学对于顺应和促进改革开放、增进化交流和拓展学习未来发展空间等具有重要的意义，可以采取在加强语教学基础上实施双语教学、学科教学内容和难度适度后移、加强双语教学的理论研究和实验实证研究以及加快培养和培训双语教师等基本策略来推动双语教学的实施。     

论“饥饿营销”策略的负面影响和实施条件

文章在观察部分企业热衷于实施＂饥饿营销＂策略的基础上,对企业实施＂饥饿营销＂策略的负面影响进行分析,提出了＂饥饿营销＂策略的实施条件。     

How Do Instructors Explain their Thinking When Planning and Teaching?

In this exploratory study we compare and report two ways in which instructors describe their teaching: (a) thinking about a course they are teaching, (b) thinking about specific classes within that course. Extensive interviews over an extended time provided the data for analysis. At the course level, we analyzed comments about teaching decisions asked at two times: before instructors taught a course and after it was completed. At the class level, we analyzed comments about specific teaching decisions asked prior to and shortly after a particular class; of importance is that in part of the post-class interview, a video of the class helped to stimulate recall about specific class actions. The analysis, which focused on goal setting and knowledge use, demonstrated variation in levels of specificity for both goals and knowledge. In situating this study in the literature on teacher thinking, we conclude that the variation in specificity of teacher thinking in the course and class interviews represents intermediary levels between teaching conceptions and teaching actions. Our proposed model of thinking distinguishes yet provides links among conceptions, thinking related to decisions at the course and class levels, and teaching actions.     

篮球技、战术关系之特点的哲学思考

本文就篮球技术、战术关系之特点、运用哲学的观点,并结合运动实践,对其进行了探讨与论述.     

Children's Theories and the Drive to Explain

Debate has been growing in developmental psychology over how much the cognitive development of children is like theory change in science. Useful debate on this topic requires a clear understanding of what it would be for a child to have a theory. I argue that existing accounts of theories within philosophy of science and developmental psychology either are less precise than is ideal for the task or cannot capture everyday theorizing of the sort that children, if they theorize, must do. I then propose an account of theories that ties theories and explanation very closely together, treating theories primarily as products of a drive to explain. I clarify some of the positions people have taken regarding the theory theory of development, and I conclude by proposing that psychologists interested in the 'theory theory' look for patterns of affect and arousal in development that would accompany the existence of a drive to explain.     

La Meme Chose: How Mathematics Can Explain the Thinking of Children and the Thinking of Children Can Illuminate Mathematical Philosophy

This article offers a new interpretation of Piaget’s decanting experiments, employing the mathematical notion of equivalence instead of conservation. Some reference is made to Piaget’s theories and to his educational legacy, but the focus in on certain of the experiments. The key to the new analysis is the abstraction principle, which has been formally enunciated in mathematical philosophy but has universal application. It becomes necessary to identity fluid objects (both configured and unconfigured) and configured and unconfigured sets-of-objects. Issues emerge regarding the conflict between philosophic realism and anti-realism, including constructivism. Questions are asked concerning mathematics and mathematical philosophy, particularly over the nature of sets, the wisdom of the axiomatic method and aspects of the abstraction principle itself.