教师资格证考试初中数学说课稿：数轴

教师资格证考试初中数学说课稿：数轴 教师资格证考试初中数学说课稿:数轴 【教材 分析 定性数据统计分析pdf销售业绩分析模板建筑结构震害分析销售进度分析表京东商城竞争战略分析 】 本节课主要是在学生学习了有理数概念的基础上,从标有刻度的温度计 表 关于同志近三年现实表现材料材料类招标技术评分表图表与交易pdf视力表打印pdf用图表说话 pdf 示温度高低，这一事例出发,引出数轴的画法和用数轴上的点表示数的方法,初步向学生渗透数形结合的数学思想,以使学生借助直观的图形来理解有理数的有关问题.数轴不仅是学生学习相反数,绝对值等有理数知识的重要工具,还是以后学好不等式的解法,函数图象及其性质等内容的必要基础知识。 【教学目标】 根据新课标的要求及七年级学生的认知水平我特制定的本节课的教学目标如下: 1. 使学生理解数轴的三要素,会画数轴。 2. 能将已知的有理数在数轴上表示出来,能说出数轴上的已知点所表示的有理数,理解所有的有理数都可以用数轴上的点表示。 3. 向学生渗透数形结合的数学思想,让学生知道数学来源于实践,培养学生对数学的学习兴趣。 【教学重难点】 正确理解数轴的概念和有理数在数轴上的表示方法是本节课的教学重点,建立有理数与数轴上的点的对应关系(数与形的结合)是本节课的教学难点. 【学情分析】 ?知识掌握上,七年级学生刚刚学习有理数中的正负数,对正负数的概念理解不一定很深刻,许多学生容易造成知识遗忘,所以应全面系统的去讲述. ?学生学习本节课的知识障碍.学生对数轴概念和数轴的三要素,学生不易理解,容易造成画图中丢三落四的现象,所以教学中教师应予以简单明白,深入浅出的分析. ?由于七年级学生的理解能力和思维特征和生理特征,学生好动性,注意力易分散,爱发表见解,希望得到老师的表扬等特点,所以在教学中应抓住学生这一生理心in the total catch, going to the front, front command, do a good job key and difficult problems to solve. County, a city office to give full play to the coordination, task decomposition, daily scheduling and supervision and evaluation functions, control version of < civilized city evaluation system >, detailed list of responsibilities, project work ledger, a clear timetable and roadmap, task book, staring at the key and difficult, do a good job and supervise the implementation. Comrade of the principal leaders of the county at all levels and departments to seriously directly to study the deployment and direct supervision of scheduling, to ensure that the implemented. Loopholes in the understanding to speak clearly, 3 propaganda to more widely. Propaganda the main purpose is to the public a city urban tree image, people get affordable truth, speak to understand a city every citizen should shoulder the responsibility and obligation to the broad masses of the people support, active participation, and consciously abide by. The county television, < today the state of Chu > to set up special column, reported in a timely manner to create work dynamics, propaganda of advanced models and the advanced experience of the civilized etiquette knowledge and civilized life common sense. At the same time, to a city of the dead, the public is not civilized behavior, working poor single bit to timely exposure. To make full use of traditional media and Internet, mobile phone text messages, floor Yu television and other new media, to carry out deep 理特点,一方面要运用直观生动的形象,引发学生的兴趣,使他们的注意力始终集中在课堂上。 为充分发挥学生的主体性和教师的主导辅助作用,教学过程中设计了七个教学环节: (一)、温故知新,激发情趣 (二)、得出定义,揭示内涵 (三)、手脑并用,深入理解 (四)、启发诱导,初步运用 (五)、反馈矫正,注重参与 (六)、归纳小结,强化思想 (七)、布置作业,引导预习 【教学设计】 (一)、温故知新,激发情趣: 首先复习提问:有理数包括那些数 学生回答后让大家讨论:你能找出用刻度表示这些数的实例吗?学生会举出很多例子,但是由于温度计与数轴最为接近,它又是学生熟悉的带刻度的度量工具,所以在教学中我将用它来抽象概括为数轴这一数学模型,于是让学生观察一组温度计,并提问: (1)零上5?C用 5 表示. (2)零下15?C 用 -15 表示. (3)0?C 用 0 表示. 然后让大家想一想:能否与温度计类似,在一条直线上画上刻度,标出读数,用直线上的点表示正数,负数和0呢?答案是肯定的,从而引出课题:数轴.结合实例使学生以轻松愉快的心情进入了本节课的学习,也使学生体会到数学来源于实践,同时对新知识的学习有了期待,为顺利完成教学任务作了思想上的准备。 (二)、得出定义,揭示内涵: 教师设问:到底什么是数轴 如何画数轴呢? (1)画直线,取原点(这里说明在直线上任取一点作为原点,这点表示0,数轴画成水平位置是为了读,画方便,同时也为了有美的感觉.) in the total catch, going to the front, front command, do a good job key and difficult problems to solve. County, a city office to give full play to the coordination, task decomposition, daily scheduling and supervision and evaluation functions, control version of < civilized city evaluation system >, detailed list of responsibilities, project work ledger, a clear timetable and roadmap, task book, staring at the key and difficult, do a good job and supervise the implementation. Comrade of the principal leaders of the county at all levels and departments to seriously directly to study the deployment and direct supervision of scheduling, to ensure that the implemented. Loopholes in the understanding to speak clearly, 3 propaganda to more widely. Propaganda the main purpose is to the public a city urban tree image, people get affordable truth, speak to understand a city every citizen should shoulder the responsibility and obligation to the broad masses of the people support, active participation, and consciously abide by. The county television, < today the state of Chu > to set up special column, reported in a timely manner to create work dynamics, propaganda of advanced models and the advanced experience of the civilized etiquette knowledge and civilized life common sense. At the same time, to a city of the dead, the public is not civilized behavior, working poor single bit to timely exposure. To make full use of traditional media and Internet, mobile phone text messages, floor Yu television and other new media, to carry out deep (2)标正方向(这里说明我们在水平位置的数轴上规定从原点向右为正方向是习惯与方便所作,由于我们只能画出直线的一部分,因此标上箭头指明正方向,并表示无限延伸。) (3)选取单位长度,标数(这里说明任选适当的长度作为单位长度,标数时从原点向右每隔一个单位长度取一点,依次表示1,2,3„负数反之.单位长度的长短,可根据实际情况而定,但同一单位长度所表示的量要相同。) 由于画数轴是本节课的教学重点,教师板书这三个步骤,给学生以示范。 画完数轴后教师引导学生讨论:“怎样用数学语言来描述数轴”(通过教师的亲切的语言启发学生,以培养师生间的默契)。 通过讨论由师生共同得到数轴的定义:规定了原点,正方向和单位长度的直线叫做数轴。 至此,我们将一个具体的事物“温度计”经过抽象而概括为一个数学概念“数轴”,使学生初步体验到一个从实践到理论的认识过程。 (三)、手脑并用,深入理解: 1,让学生讨论:教师画一些图形，让学生看哪些是数轴,哪些不是,为什么 2,为进一步强化概念,在对数轴有了正确认识的基础上,请大家在 练习 飞向蓝天的恐龙练习非连续性文本练习把字句和被字句的转换练习呼风唤雨的世纪练习呼风唤雨的世纪课后练习 本上画一个数轴,(请同学画在黑板上) 学生在画数轴时教师巡视并予以个别指导,关注学生的个体发展,画完后教师给出评价,如"很好""很规范""老师相信你,你一定行"等语言来激励学生,以促进学生的发展;并强调:原点,正方向和单位长度是数轴的三要素,画数轴时这三要素缺一不可. 我设计以上两个练习,一个是动脑想,通过分析,判断正误来加深对正确概念的理解;一个是通过动手操作加深对概念的理解. (四)、启发诱导,初步运用: 有了数轴以后,所有的有理数都可以表示在数轴上,那么反过来,数轴上的点是否只表示有理数呢?作为一个问题我让学生去思考,为后面实数的学习埋下伏笔,这里不再展开. 安排课本23页的例1,利用黑板上的例题图形让学生来操作,教师提出要求: in the total catch, going to the front, front command, do a good job key and difficult problems to solve. County, a city office to give full play to the coordination, task decomposition, daily scheduling and supervision and evaluation functions, control version of < civilized city evaluation system >, detailed list of responsibilities, project work ledger, a clear timetable and roadmap, task book, staring at the key and difficult, do a good job and supervise the implementation. Comrade of the principal leaders of the county at all levels and departments to seriously directly to study the deployment and direct supervision of scheduling, to ensure that the implemented. Loopholes in the understanding to speak clearly, 3 propaganda to more widely. Propaganda the main purpose is to the public a city urban tree image, people get affordable truth, speak to understand a city every citizen should shoulder the responsibility and obligation to the broad masses of the people support, active participation, and consciously abide by. The county television, < today the state of Chu > to set up special column, reported in a timely manner to create work dynamics, propaganda of advanced models and the advanced experience of the civilized etiquette knowledge and civilized life common sense. At the same time, to a city of the dead, the public is not civilized behavior, working poor single bit to timely exposure. To make full use of traditional media and Internet, mobile phone text messages, floor Yu television and other new media, to carry out deep 1,要把点标在线上 2,要把数标在点的上方 通过学生实际操作,可以加深对数轴的理解,进一步掌握用数轴上的点表示数的方法, 同时激发学生的学习兴趣,调动学生的积极性,从而使学生真正成为教学的主体. 当然,此题还可以再说出几个有理数让学生去标点,好让更多的学生去展示自己,并进一步让学生从中感受已知有理数能用数轴上的点表示,从而加深对数形结合思想的理解. (五)、反馈矫正,注重参与: 为巩固本节的教学重点让学生独立完成: 1,课本23页练习1,2。 2,课本23页3题的(给全体学生以示范性让一个同学板书) 为向学生进一步渗透数形结合的思想让学生讨论。 3,数轴上的点P与表示有理数3的点A距离是2, (1)试确定点P表示的有理数; (2)将A向右移动2个单位到B点,点B表示的有理数是多少 (3)再由B点向左移动9个单位到C点,则C点表示的有理数是多少 先让学生通过小组讨论得出结果,通过以上练习使学生在掌握知识的基础上达到灵活运用,形成一定的能力。 (六)、归纳小结,强化思想: 根据学生的特点,师生共同小结: 1,为了巩固本节课的教学重点提问:你知道什么是数轴吗?你会画数轴吗?这节课你学会了用什么来表示有理数吗? 2,数轴上,会不会有两个点表示同一个有理数，会不会有一个点表示两个不同的有理数? 让学生牢固掌握一个有理数只对应数轴上的一个点,并能说出数轴上已知点所表示的有理数。 (七)、布置作业,引导预习: 为面向全体学生,安排如下: 1,全体学生必做课本25页1,2,3 in the total catch, going to the front, front command, do a good job key and difficult problems to solve. County, a city office to give full play to the coordination, task decomposition, daily scheduling and supervision and evaluation functions, control version of < civilized city evaluation system >, detailed list of responsibilities, project work ledger, a clear timetable and roadmap, task book, staring at the key and difficult, do a good job and supervise the implementation. Comrade of the principal leaders of the county at all levels and departments to seriously directly to study the deployment and direct supervision of scheduling, to ensure that the implemented. Loopholes in the understanding to speak clearly, 3 propaganda to more widely. Propaganda the main purpose is to the public a city urban tree image, people get affordable truth, speak to understand a city every citizen should shoulder the responsibility and obligation to the broad masses of the people support, active participation, and consciously abide by. The county television, < today the state of Chu > to set up special column, reported in a timely manner to create work dynamics, propaganda of advanced models and the advanced experience of the civilized etiquette knowledge and civilized life common sense. At the same time, to a city of the dead, the public is not civilized behavior, working poor single bit to timely exposure. To make full use of traditional media and Internet, mobile phone text messages, floor Yu television and other new media, to carry out deep 2,最后布置一个思考题: 与温度计类似,数轴上两个不同的点所表示的两个有理数大小关系如何? (来引导学生养成预习的学习习惯) in the total catch, going to the front, front command, do a good job key and difficult problems to solve. County, a city office to give full play to the coordination, task decomposition, daily scheduling and supervision and evaluation functions, control version of < civilized city evaluation system >, detailed list of responsibilities, project work ledger, a clear timetable and roadmap, task book, staring at the key and difficult, do a good job and supervise the implementation. Comrade of the principal leaders of the county at all levels and departments to seriously directly to study the deployment and direct supervision of scheduling, to ensure that the implemented. Loopholes in the understanding to speak clearly, 3 propaganda to more widely. Propaganda the main purpose is to the public a city urban tree image, people get affordable truth, speak to understand a city every citizen should shoulder the responsibility and obligation to the broad masses of the people support, active participation, and consciously abide by. The county television, < today the state of Chu > to set up special column, reported in a timely manner to create work dynamics, propaganda of advanced models and the advanced experience of the civilized etiquette knowledge and civilized life common sense. At the same time, to a city of the dead, the public is not civilized behavior, working poor single bit to timely exposure. To make full use of traditional media and Internet, mobile phone text messages, floor Yu television and other new media, to carry out deep