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北师大初中八年级数学下册分式的有关概念教案
解析：由分式有意义的条件得3x－1≠0，解得x≠13.则分式无意义的条件是x＝13，故选C.方法总结：分式无意义的条件是分母等于0.【类型三】 分式值为0的条件若使分式x2－1x＋1的值为零，则x的值为()A．－1 B．1或－1C．1 D．1和－1解析：由题意得x2－1＝0且x＋1≠0，解得x＝1，故选C.方法总结：分式的值为零的条件：(1)分子为0；(2)分母不为0.这两个条件缺一不可．三、板书设计1．分式的概念：一般地，如果A、B表示两个整式，并且B中含有字母，那么式子AB叫做分式．2．分式AB有无意义的条件：当B≠0时，分式有意义；当B＝0时，分式无意义．3．分式AB值为0的条件：当A＝0，B≠0时，分式的值为0.本节采取的教学方法是引导学生独立思考、小组合作，完成对分式概念及意义的自主探索．提出问题让学生解决，问题由易到难，层层深入，既复习了旧知识又在类比过程中获得了解决新知识的途径．在这一环节提问应注意循序性，先易后难、由简到繁、层层递进，台阶式的提问使问题解决水到渠成.
第四单元《教学设计》 说课稿 2021—2022学年统编版高中语文必修下册
（六）说教学策略1.专题性海量的媒介信息必须加以选择或者整合，以项目为依据，进行信息筛选，形成专题性阅读与交流；培养学生对文本信息“化零为整”的能力，提升跨媒介阅读与交流学习的充实感。2.情境化情境教学应指向学生的应用，建构富有符合时代气息的内容，与生活经验更加贴合，对学生的语言建构与运用有所提升，在情境中能够有效地进行交流。3.任务化以任务为导向的序列化学习，可以为学生构建学习路线图、学习框架等具体任务引导；或以跨媒介的认识与应用为任务的设置引导；甚至以阅读和交流作为序列化安排的实践引导。4.整合性跨媒介阅读与交流是结合线上线下的资源，形成新的“超媒介”，也能实现对信息进行“深加工”，多种媒介的信息整合只为一个核心教学内容服务。5.互文性语言文字是语文之生命，我们是立足于语言文字的探讨，音乐、图像、视频等文本与传统语言文字文本形成互文，触发学生对学习内容立体化和具体化的感悟，提升学生的审美能力。
小学数学人教版四年级上册《认识计算器及其计算方法》说课稿
“用计算器计算”是江苏国标版四年级上册数学第十一单元的教学内容这部分内容是在学生熟练掌握了整数的四则计算法则及两步混合运算的基础上进行教学。通过学习使学生可以借助计算器进行较大数目的四则运算并借助计算器来探索有关规律有利于帮助学生形成初步的探索和解决问题的能力。 本单元内容分两段安排，第一段先认识计算器了解计算器的基本功能和操作方法再学习用计算器进行四则计算的方法。第二段教学用计算器进行两步混合运算并安排了练习十。教材在“想想做做”和练习十中还编排了一些探索数学规律的趣题并通过“你知道吗”介绍“改错键”等常用的功能键以及有关计算工具发展的历史让学生了解计算工具的演变过程感受人类科技的进步与发展。最后教材还安排了实践活动《一亿有多大》帮助学生形成良好的数感。本单元分四课时完成今天我说的是第一课时。
人教版高中地理选修3第一章第二节现代旅游对区域发展的意义教案
三、影响区域环境说明：环境是旅游业的基础，旅游对环境保护具有促进作用。世界上很多国家在发展旅游业的同时，都很重视对旅游资源和环境的保护，以实现旅游业的可持续发展。旅游业的发展对环境也有消极作用，如果旅游与环境的关系不处理好，环境也会朝着恶化的方向发展。图1．10古建修复图1．10对比显示古建筑修复前后景观的变化，说明旅游业的发展有利于文物古迹和古建筑的保护。讨论：1．列举旅游业发展有利于环境的措施。提示：建立各种自然保护区、申报历史文物保护单位等措施都有利于保护旅游环境。2．举例说明旅游对环境的消极作用。提示：旅游对环境的消极作用主要表现在：由于对旅游资源开发建设不当或失误，使生态环境恶化；由于大量游客的涌入，排放的各类废弃物超过了环境自净能力而造成环境污染；由于大量游客的接触或不文明行为引起的对风景、文物的破坏等。
北师大初中数学八年级上册二次根式及其化简1教案
方法总结：(1)若被开方数中含有负因数，则应先化成正因数，如(3)题．(2)将二次根式尽量化简，使被开方数(式)中不含能开得尽方的因数(因式)，即化为最简二次根式(后面学到)．探究点三：最简二次根式在二次根式8a，c9，a2＋b2，a2中，最简二次根式共有()A．1个 B．2个C．3个 D．4个解析：8a中有因数4；c9中有分母9；a3中有因式a2.故最简二次根式只有a2＋b2.故选A.方法总结：只需检验被开方数是否还有分母，是否还有能开得尽方的因数或因式．三、板书设计二次根式定义形如a（a≥0）的式子有意义的条件：a≥0性质：（a）2＝a（a≥0），a2＝a（a≥0）最简二次根式本节经历从具体实例到一般规律的探究过程，运用类比的方法，得出实数运算律和运算法则，使学生清楚新旧知识的区别和联系，加深学生对运算法则的理解，能否根据问题的特点，选择合理、简便的算法，能否确认结果的合理性等等．
北师大初中数学八年级上册二次根式及其化简2教案
属于此类问题一般有以下三种情况①具体数字，此时化简的条件已暗中给定，②恒为非负值或根据题中的隐含条件，如（1）小题。③给出明确的条件，如（2）小题。第二类，需讨论后再化简。当题目中给定的条件不能判定绝对值符号内代数式值的符号时，则需讨论后化简，如（4）小题。例3．已知a+b=-6,ab=5，求 的值。解：∵ab=5>0,∴a,b同号，又∵a+b=-6<0,∴a<0,b<0∴ .说明：此题中的隐含条件a<0,b<0不能忽视。否则会出现错误。例4．化简： 解：原式=|x-6|-|1+2x|+|x+5|令x-6=0，得x=6，令1+2x=0，得 ，令x+5=0，得x=-5.这样x=6, ,x=-5，把数轴分成四段（四个区间）在这五段里分别讨论如下：当x≥6时，原式=(x-6)-(1+2x)+(x+5)=-2.当 时，原式=-(x-6)-(1+2x)+(x+5)=-2x+10.当 时，原式=-(x-6)-[-(1+2x)]+(x+5)=2x+12.当x<-5时，原式=-(x-6)+(1+2x)-(x+5)=2.说明：利用公式 ，如果绝对值符号里面的代数式的值的符号无法决定，则需要讨论。方法是：令每一个绝对值内的代数式为零，求出对应的“零点”，再用这些“零点”把数轴分成若干个区间，再在每个区间内进行化简。
人教部编版语文八年级下册名著导读《傅雷家书》 选择性阅读教案
评价：这段话表明傅雷朋友的角色。他把孩子当成朋友，为人生得一知己而感到兴奋、自豪。在读这段话时声音应洪亮，感情应充沛。小结：我们组还发现傅雷对傅聪的称呼有很多，如聪、聪儿、孩子、亲爱的聪、亲爱的孩子。有时两个同时用，比如“聪，亲爱的孩子！”一直以来，我们都觉得父爱不善表达，可是傅雷的这些亲昵直白的称呼表达了他对傅聪的爱，是这么的温柔，如慈母一般。所以，读这些称呼时我们要读得轻柔深情些。【设计意图】这一环节不仅能展示学生的阅读成果，还能使学生感受到阅读的成就感，并在相互交流中产生更深刻的理解和感悟，在朗读和评价中体会父爱。二、感悟成长1.解读“虎爸”师：在同学们的阅读分享中，傅雷这样一个深爱儿子的父亲形象深入人心。其实，傅雷早期对傅聪的教育是很严苛的，是一个“虎爸”的形象。我们一起来看一则小故事。
人教版新课标小学数学六年级下册比例的意义和基本性质说课稿2篇
4.教学比例的各部分名称这部分的教学，我采用了阅读自学法。实施素质教育，使学生由“学会”变“会学”，这里我注重培养学生的自学能力，师生的双边关系亦实现从扶到放的转变。在学生自学课本时，老师写出比例的两种形式，引导学生注意内项和外项的位置。5.教学比例的基本性质观察80：2＝200：5中的两个内项的积与两个外项的积的关系，引导学生把两个外项与两个内项分别相乘，比较结果，然后引导他们回答：2：3 ＝ 0.4：0.6。两个内项的积与两个外项的积有什么关系？再让学生归纳出比例的基本性质，探讨写分数形式，归纳“交叉相乘”积相等。小结：比例的基本性质可以检验组成的比例对不对？并提问：4：9＝5：10成立吗？比例的基本性质是本课的第二个重点。为了突出重点，我引导学生通过计算几个比例式的内项积和外项积，也从特殊到一般的推理方式，引导学生发现规律，总结概括性质。同时也渗透了实践第一的观点。
北师大初中数学九年级上册位似多边形及其性质2教案
（3）分别在射线OA，OB，OC，OD上取点A′、B′、C′、D′，使得 ；（4）顺次连接A ′B′、B′C′、C′D′、D′A′，得到所要画的四边形A′B′C′D′，如图2．问：此题目还可以 如何画出图形？作法二 ：（1）在四边形ABCD外任取一点 O；（2）过点O分别作射线OA， OB， OC，OD；（3）分别在射线OA， OB， OC， OD的反向延长线上取点A′、B′、C′、D′，使得 ；（4）顺次连接A ′B′、B′ C′、C′D′、D′A′，得到所 要画的四边形A′B′C′D′，如图3． 作法三：（1）在四边形ABCD内任取一点O；（2）过点O分别作 射线OA，OB，OC，OD；（3）分别在射线OA，OB，OC，OD上取点A′、B′、C′、D′，使得 ；（4）顺次连接A′B′、B′C ′、C′D′、D′A′，得到所要画的四边形A′B′C′D′，如图4．（当点O在四边形ABCD的一条边上或在四边形ABCD的一个顶点上时，作法略——可以让学生自己完成）三、课堂练习 活动3 教材习题小结：谈谈你这节课学习的收获．
北师大初中数学九年级上册位似多边形及其性质1教案
①分别连接OA，OB，OC，OD，OE；②分别在AO，BO，CO，DO，OE上截取OA′，OB′，OC′，OD′，OE′，使OA′OA＝OB′OB＝OC′OC＝OD′OD＝OE′OE＝13；③顺次连接A′B′，B′C′，C′D′，D′E′，E′A′.五边形A′B′C′D′E′就是所求作的五边形；（3）画法如下：①分别连接AO，BO，CO，DO，EO，FO并延长；②分别在AO，BO，CO，DO，EO，FO的延长线上截取OA′，OB′，OC′，OD′，OE′，OF′，使OA′OA＝OB′OB＝OC′OC＝OD′OD＝OE′OE＝OF′OF＝12；③顺次连接A′B′，B′C′，C′D′，D′E′，E′F′，F′A′.六边形A′B′C′D′E′F′就是所求作的六边形.方法总结：（1）画位似图形时，要注意相似比，即分清楚是已知原图与新图的相似比，还是新图与原图的相似比.（2）画位似图形的关键是画出图形中顶点的对应点.画图的方法大致有两种：一是每对对应点都在位似中心的同侧；二是每对对应点都在位似中心的两侧.（3）若没有指定位似中心的位置，则画图时位似中心的取法有多种，对画图而言，以多边形的一个顶点为位似中心时，画图最简便.三、板书设计
人教版新课标小学数学六年级上册分数除法的意义和分数除以整数说课稿
师：这是一种较为简便、应用广泛的方法，但有时候也要具体问题具体分析，做题时要合理灵活地选择计算方法。《研究学生如何学比研究教师如何教更重要。学生对新知识的学习必须以已有的知识和学习经验作为基础，因此正确分析学生的知识基础和学习经验就显得格外重要。我认为分数除以整数的教学基础在于以下几点：分数与小数的转化；分数的意义；分数乘法的意义；倒数的知识；商不变的性质等。这些知识在以前的学习中，学都有了足够的掌握。有了上面的分析基础，我觉得把研究新知识的权力教给学生，是完全可以的。》4、质疑与反思。师：对于这些方法，尽管大家的思维角度不尽相同，但是基本的想法是相同的，想一想我们是怎样解决问题的？生：用学过的倒数、商不变的性质解决的。师：对。用一句话概括就是运用旧知识解决新新问题。这是一种很重要的学习方法。5、实践体验练习巩固。
人教版新课标小学数学六年级上册分数除法的意义和整数除以分数说课稿
一．说教材。我说课的内容是人教版课程标准实验教科书六年级上册的分数除法单元中的例1和例2。例1是分数除法的意义认识，例2是分数除以整数的计算。在这之前学生已经掌握了整数除法的意义和分数乘法的意义及计算，而本课的学习将为统一分数除法计算法则打下基础。例1先是整数除法回顾，再由100克=1/10千克，从而引出分数除法算式，通过类比使学生认识到分数除法的意义与整数除法的意义相同，都是‘已知两个因数的积和其中一个因数，求另一个因数的运算’。例2是分数除以整数的计算教学，意在通过让学生进行折纸实验、验证，引导学生将‘图’和‘式’进行对照分析，从而发现算法，感悟算理，同时也初步感受数形结合的思想方法。根据刚才对教材的理解，本节课的教学目标是：1、理解分数除法的意义与整数除法的意义相同。2．理解分数除以整数的计算原理，掌握计算方法，并能正确的进行计算。
数据的整理教案教学设计
一、课前准备师：同学们想一想，你同父母一起去商店买衣服时，衣服上的号码都有哪些，标志是什么？学生：我看到有些衣服上标有M、S、L、XL、XXL等号码．但我不清楚代表的具体范围，适合什么人穿，但肯定与身高、胖瘦有关．师：这位同学很善动脑，也爱观察．S代表最小号，身高在150~155cm的人适合穿S号．M号适合身高在155~160cm的人着装……厂家做衣服订尺寸也并不是按所有人的尺寸定做，而是按某个范围分组批量生产．你觉得这种生产方法有什么优点？学校要为同学们订制校服，为此小明调查了他们班50名同学的身高，结果(单位cm)．如下
新人教版高中英语选修2Unit 2 Reading for writing教学设计
The theme of this section is to express people's views on studying abroad. With the continuous development of Chinese economic construction, especially the general improvement of people's living standards, the number of Chinese students studying abroad at their own expense is on the rise. Many students and parents turn their attention to the world and regard studying abroad as an effective way to improve their quality, broaden their horizons and master the world's advanced scientific knowledge, which is very important for the fever of going abroad. Studying abroad is also an important decision made by a family for their children. Therefore, it is of great social significance to discuss this issue. The theme of this section is the column discussion in the newspaper: the advantages and disadvantages of studying abroad. The discourse is about two parents' contribution letters on this issue. They respectively express their own positions. One thinks that the disadvantages outweigh the advantages, and the other thinks that the advantages outweigh the disadvantages. The two parents' arguments are well founded and logical. It is worth noting that the two authors do not express their views on studying abroad from an individual point of view, but from a national or even global point of view. These two articles have the characteristics of both letters and argumentative essays1.Guide the students to read these two articles, and understand the author's point of view and argument ideas2.Help the students to summarize the structure and writing methods of argumentative writing, and guides students to correctly understand the advantages and disadvantages of studying abroad3.Cultivate students' ability to analyze problems objectively, comprehensively and deeply
新人教版高中英语选修2Unit 3 Using langauge-Listening教学设计
1． How is Hunan cuisine somewhat different from Sichuan cuisine?The heat in Sichuan cuisine comes from chilies and Sichuan peppercorns. Human cuisine is often hotter and the heat comes from just chilies.2.What are the reasons why Hunan people like spicy food?Because they are a bold people. But many Chinese people think that hot food helps them overcome the effects of rainy or wet weather.3.Why do so many people love steamed fish head covered with chilies?People love it because the meat is quite tender and there are very few small bones.4.Why does Tingting recommend bridge tofu instead of dry pot duck with golden buns?Because bridge tofu has a lighter taste.5 .Why is red braised pork the most famous dish?Because Chairman Mao was from Hunan, and this was his favorite food.Step 5: Instruct students to make a short presentation to the class about your choice. Use the example and useful phrases below to help them.? In groups of three, discuss what types of restaurant you would like to take a foreign visitor to, and why. Then take turns role-playing taking your foreign guest to the restaurant you have chosen. One of you should act as the foreign guest, one as the Chinese host, and one as the waiter or waitress. You may start like this:? EXAMPLE? A: I really love spicy food, so what dish would you recommend?? B: I suggest Mapo tofu.? A: Really ? what's that?
新人教版高中英语选修2Unit 5 Learning about Language教学设计
The purpose of this section of vocabulary exercises is to consolidate the key words in the first part of the reading text, let the students write the words according to the English definition, and focus on the detection of the meaning and spelling of the new words. The teaching design includes use English definition to explain words, which is conducive to improving students' interest in vocabulary learning, cultivating their sense of English language and thinking in English, and making students willing to use this method to better grasp the meaning of words, expand their vocabulary, and improve their ability of vocabulary application. Besides, the design offers more context including sentences and short passage for students to practice words flexibly.1. Guide students to understand and consolidate the meaning and usage of the vocabulary in the context, 2. Guide the students to use the unit topic vocabulary in a richer context3. Let the students sort out and accumulate the accumulated vocabulary, establishes the semantic connection between the vocabulary,4. Enable students to understand and master the vocabulary more effectivelyGuiding the Ss to use unit topic words and the sentence patterns in a richer context.Step1: Read the passage about chemical burns and fill in the blanks with the correct forms of the words in the box.
新人教版高中英语选修2Unit 5 Reading and thinking教学设计
The theme of this activity is to learn the first aid knowledge of burns. Burns is common in life, but there are some misunderstandings in manual treatment. This activity provides students with correct first aid methods, so as not to take them for granted in an emergency. This section guides students to analyze the causes of scald and help students avoid such things. From the perspective of text structure and collaborative features, the text is expository. Expository, with explanation as the main way of expression, transmits knowledge and information to readers by analyzing concepts and elaborating examples. This text arranges the information in logical order, clearly presents three parts of the content through the subtitle, accurately describes the causes, types, characteristics and first aid measures of burns, and some paragraphs use topic sentences to summarize the main idea, and the level is very clear.1. Guide students to understand the causes, types, characteristics and first aid methods of burns, through reading2. Enhance students’ ability to deal withburnss and their awareness of burns prevention3. Enable students to improve the ability to judge the types of texts accurately and to master the characteristics and writing techniques of expository texts.Guide students to understand the causes, types, characteristics and first aid methods of burns, through readingStep1: Lead in by discussing the related topic:1. What first-aid techniques do you know of ?CPR; mouth to mouth artificial respiration; the Heimlich Manoeuvre
新人教版高中英语选修2Unit 4 Reading and thinking教学设计
【词汇精讲】highlight n.最好或最精彩的部分 vt.突出;强调;使醒目One of the highlights of the trip was seeing the Taj Mahal.这次旅行的亮点之一是参观泰姬陵。Your resume should highlight your skills and achievements.你的简历应该突出你的技能和成就。The report highlights the major problems facing society today.报告强调了当今社会所面临的主要问题。I’ve highlighted the important passages in yellow.我用黄色标出了重要段落。7.Edmonton is freezing cold in winter,with daily temperatures averaging -10 ℃.埃德蒙顿冬季寒冷,日平均气温为-10°C。【词汇精讲】freezing adj.极冷的;冰冻的Leave a basin of water outside in freezing weather.在冰冻的天气里,放一盆水在室外。It’s freezing cold outside so wear a warm coat.外面超冷的,所以穿一个暖和一点的外套吧。8.It was not until 9:30 a.m.that they finally reached the capital of Ontario,Toronto.直到上午9时30分,他们才终于到达多伦多的首府安大略省。【句式剖析】本句是一个强调句,强调的是句子的时间状语until 9:30。含有not...until...的句子的强调句为It is not until...that...,that后面的句子要用肯定形式。It was not until then that I suddenly realized nobody was happier than I was.直到那时我才突然意识到没有人比我更幸福了。
新人教版高中英语选修2Unit 3 Learning about Language教学设计
1. We'll need ten months at least to have the restaurant decorated.2.Some traditional Chinese dishes from before the Ming Dynasty are still popular today.3.My grandpa's breakfast mainly includes whole grain biscuits and a glass of milk.4.People in this area would eat nearly a kilo of cheese per week.5. We enjoyed a special dinner in a fancy restaurant where the waiters all wore attractive suits.6. He prefers this brand of coffee which, as he said, has an unusually good flavor.Key:1. at a minimum 2. prior to3. consist of4. consume5. elegant6. exceptionalStep 5：Familiarize yourself with some food idioms by matching the meaning on the right with the colored words on the left.1.Public concern for the health of farm animals has mushroomed in the UK2.Anderson may be young but he's certainly rolling to doing dough!3.George is a popular lecturer. He often peppers his speech with jokes.4.As the person to bring home the bacon, he needs to find a stable job.5 He is often regarded as a ham actor for his over emphasized facial expressions. The media reported that these companies had treated pollution as a hot potato. 6.The media reported that these companies had treated pollution as a hot potato.7.Don't worry about the test tomorrow. It's going to be a piece of cake!8. It's best to fold the swimming ring when it is as flat as a pancake.A. completely flatB. something that is very easy to do C.an issue that is hard to deal withD.to include large numbers of somethingE.to earn on e's living to support a familyF. wealthyG.to rapidly increase in numberH. an actor who performs badly, especially by over emphasizing emotions
新人教版高中英语选修2Unit 2 Learning about Language教学设计
The activity theme of this section is to design various activities around the key words in the first text. Therefore, the activities require students to pay attention to the spelling of words. On the other hand, let students grasp the meaning of words more accurately through sentences and short texts. This kind of teaching design also helps to improve the ability of using English thinking.1. Cultivating students' ability to use word formation to induce and memorize vocabulary, and the ability to use lexical chunks to express meaning.2. Guide the students to think independently and use the correct form of words to complete sentences3. Cultivate students' habit of using lexical chunks to express language completely, guide students to draw words in sentences quickly, pay attention to word collocation, so as to accumulate more authentic expressions4. Instruct students to create sentences with the chunks.1. Enable students to use the language points in the real situation or specific contexts flexibly and appropriately.2. Guiding the Ss to use unit topic words and the sentence patterns in a richer context.Step1: Think of a word that best fits each definition.1. to remember sth2.to accept, admit, or recognize sth or the truth/existence of sth3. the process of changing sth or yourself to suit a new situation4 .to make sb feel less worried or unhappy5. a strong desire to achieve sth
