(设计意图:因为圆中有关的点、线、角及其他图形位置关系的复杂,学生往往因对已知条件的分析不够全面,忽视某个条件,某种特殊情况,导致漏解。采用小组讨论交流的方式进行要及时进行小组评价。)(3) 议一议( 如图,OA、OB、OC都是圆O的半径∠AOB=2∠BOC, 求证:∠ACB=2∠BAC。)(设计意图:通过练习,使学生能灵活运用圆周角定理进行几何题的证明,规范步骤,提高利用定理解决问题的能力。)(三)说小结首先,通过学生小组交流,谈一谈你有什么收获。(提示学生从三方面入手:1、学到了知识;2、掌握了哪些数学方法;3、体会到了哪些数学思想。)然后,教师引导小组间评价。使学生对本节内容有一个更系统、深刻的认识,实现从感性认识到理性认识的飞跃。(四)、板书设计为了集中浓缩和概括本课的教学内容,使教学重点醒目、突出、合理有序,以便学生对本课知识点有了完整清晰的印象。我只选择了本节课的两个知识点作为板书。
设计意图这一组习题的设计,让每位学生都参与,通过学生的主动参与,让每一位学生有“用武之地”,深刻体会本节课的重要内容和思想方法,体验学习数学的乐趣,增强学习数学的愿望与信心。4.回顾反思,拓展延伸(教师活动)引导学生进行课堂小结,给出下列提纲,并就学生回答进行点评。(1)通过本节课的学习,你学会了哪些判断直线与圆位置关系的方法?(2)本节课你还有哪些问题?(学生活动)学生发言,互相补充。(教师活动)布置作业(1)书面作业:P70练习8.4.41、2题(2)实践调查:寻找圆与直线的关系在生活中的应用。设计意图通过让学生课本上的作业设置,基于本节课内容和学生的实际,对课后的书面作业分为三个层次,分别安排了基础巩固题、理解题和拓展探究题。使学生完成基本学习任务的同时,在知识拓展时起激学生探究的热情,让每一个不同层次的学生都可以获得成功的喜悦。
通过与学生讲解切线长定义,让学生在参与、合作中有一个猜想,再进一步提出更有挑战性的问题,能否用数学的方法加以证明。问题的解决,使学生既能解决新的问题,同时应用到全等、切线的性质等知识,同时三条辅助线中,两条运用切线性质添加、一条构造全等。证明后用较规范的语言归纳并不断完善。(3) 应用新知加深理解通过前面的学习学生们已经对切线长定理有了较深刻的了解。为了加深学生对定理的认识并培养学生的应用意识学习例1、例2。例1让学生自己独立完成,加深对切线长定理的理解,老师进行点评,对于例2,由师生共同分析完成,交进行示范板书。(4) 巩固与提高此训练题分为二个层次,目的在于巩固新学的定理,并将所学的定理应用到旧的知识体系中,使学生的知识体系得到补充和完善。(5) 归纳与小结通过小结,使知识成为系统帮助学生全面理解,掌握所学的知识。
5、课本练习:P129引导学生运用随机数表来模拟试验过程并给予解答。问题2:有四个阄,其中两个分别代表两件奖品,四个人按顺序依次抓阄来决定这两件奖品的归属,先抓的人中奖率一定大吗?教法:可组织学生用试验的方法来说明问题,对于试验的结果是有说服力的,很容易使学生相信摸奖的次序对中奖的概率没有影响。问题3:彩民甲研究了近几期这种体育彩票的中奖号码,发现数字06和08出现的次数最多,他认为,06和08是“幸运号码”,因此,他在所买的每一注彩票中都选上了06和08。你认为他这样做有道理吗?教法说明:要让学生看到试验方法对试验结果的影响:1、 因为开奖用的36个球是均匀的、无差别的,所以每个号码被选为中奖号码的可能性是一样的,不存在“幸运号码”。
教学过程我主要分为六部分:一、新课引入,二、探究新知 ,三、巩固新知,四、感悟收获,五、布置作业,六、板书设计 (一)、新课引入教师提问:一个直角三角形中,一个锐角正弦、余弦、正切值是怎么定义的? sinA如图在 Rt△ABC中,∠C=90°。(1)a、b、c三者之间的关系是 ,∠A+∠B= 。 (2)sinA=sinB= , cosB= ,tanB= 。 (3)若A=30°,则B(4)sinA和cosB有什么关系?____________________;【设计意图】回顾上节课所学的内容,便于后面教学的开展。 (二)、探究新知活动一、探索特殊角的三角函数,并填写课本表格[问题] 1、观察一副三角尺,其中有几个锐角?它们分别等于多少度? [问题] 2、sin30°等于多少呢?你是怎样得到的?与同伴交流. [问题] 3、cos30°等于多少?tan30°呢? [问题] 4、我们求出了30°角的三个三角函数值,还有两个特殊角——45°、60°,它们的三角函数值分别是多少?你是如何得到的? 1、特殊角的三角函数值表:
本节课的设计是以教学大纲和教材为依据,遵循因材施教的原则,坚持以学生为主体,充分发挥学生的主观能动性。教学过程中,注重学生探究能力的培养。还课堂给学生,让学生去亲身体验知识的产生过程,拓展学生的创造性思维。同时,注意加强对学生的启发和引导,鼓励培养学生们大胆猜想,小心求证的科学研究的思想。本节课采用教具辅助教学,旨在呈现更直观的形象,提高学生的积极性和主动性,并提高课堂效率。2、学法研究“赠人以鱼,不如授人以渔”,最有价值的知识是关于方法的知识,首先教师应创造一种环境,引导学生从已知的、熟悉的知识入手,让学生自己在某一种环境下不知不觉中运用旧知识的钥匙去打开新知识的大门,进入新知识的领域,从不同角度去分析、解决新问题,通过基础练习、提高练习和拓展练习发掘不同层次学生的不同能力,从而达到发展学生思维能力和自学能力的目的,发掘学生的创新精神。
第一道例题提示学生把地基看成一个几何图形,即正六边形,逐步引导学生完成例题的解答。例题1:有一个亭子它的地基是半径为4米的正六边形,求地基的周长和面积(精确到0.1平方米)。第二道例题,我让学生独立完成,我在下面巡视,个别辅导,同时我将关注不同层次学生对本节知识的理解、掌握程度,及时调整教学。最后,引导学生总结这一类问题的求解方法。这两道例题旨在将实际问题转化成数学问题,将多边形化归成三角形来解决,体现了化归思想的应用。(七)、课堂小结(1)学完这节课你有哪些收获?(八)布置作业:我针对学生素质的差异设计了有层次的训练题,留给学生课后自主探究,这样即使学生掌握基础知识,又使学有佘力的学生有所提高,从而达到拔尖和“减负”的目的。
当然,在讨论的过程中,对个别学生要及时点拨利用相似三角形对应边的关系来求AD,至于S与x的关系式自然是水到渠成了。接着让同学们以小组为单位,派出代表展示自己的讨论成果。然后我进一步抛出重点问题3)这里S与x是一种什么函数关系?当x 取何值时,S的值最大?最大值是多少?这个例题和刚才的做一做非常相似。那么要求矩形的面积 就必须知道矩形的长和宽,通过学生的思考、讨论、大家都明白了S与x的关系一定是二次函数,要求面积的最大值,也就是求二次函数的最大值,这样就将实际问题转化为数学问题了.简单的小组交流过后,同学们争先恐后表达自己的观点:有的小组利用的是配方法,有的小组直接利用二次函数的顶点坐标求出了最大面积。 ,我及时的鼓励学生:大家真的很棒,老师为你们骄傲,请再接再厉。
8、板书装在套子里的人别里科夫的形象——有形的套子套己——无形的套子套人第二课时合作探究:目标挖掘主题及现实意义。问题设置,衔接上节课内容,层层深入。1、结合上节课别里科夫的形象分析:他的思想被什么套住,其悲剧原因在哪?(根据人物形象的分析与社会背景的了解,直击主题。)沙皇腐朽的专制统治套住了他的思想,沙皇的清规戒律使他不敢越雷池一步,所以他是受害者,但他的身份性格以及特定的社会环境,又让他成为沙皇统治的捍卫者。2、他恋爱的情节以及科瓦连科这两个人物的塑造的意义?(从人物以及主题入手,推翻沙皇的腐朽反动的统治,必须是每一个人都敢于打破套子,唤醒革新,更新观念,拒绝腐朽。)别里科夫渴望打破束缚,也想革新,而科瓦连科两个人物体现朝气活泼,以及勇于打破常规束缚的勇气,为革新升起了一片曙光。3、塑造别里科夫的手法,除了一般刻画人物方法外,还有什么方法?
知识探究(一):普查与抽查像人口普查这样,对每一个调查调查对象都进行调查的方法,称为全面调查(又称普查)。 在一个调查中,我们把调查对象的全体称为总体,组成总体的每一个调查对象称为个体。为了强调调查目的,也可以把调查对象的某些指标的全体作为总体,每一个调查对象的相应指标作为个体。问题二:除了普查,还有其他的调查方法吗?由于人口普查需要花费巨大的财力、物力,因而不宜经常进行。为了及时掌握全国人口变动状况,我国每年还会进行一次人口变动情况的调查,根据抽取的居民情况来推断总体的人口变动情况。像这样,根据一定目的,从总体中抽取一部分个体进行调查,并以此为依据对总体的情况作出估计和判断的方法,称为抽样调查(或称抽查)。我们把从总体中抽取的那部分个体称为样本,样本中包含的个体数称为样本量。
第二学期开学安全第一课(国旗下讲话)老师同学们:大家好!今天是新学期的第一天,我们怀着激动的心情,迈着矫健的步伐回到学校,迎接新学期的挑战。今天我将利用一节课的时间围绕“安全”这个话题和大家谈起。因为安全是我们快乐学习与生活的前提,是我们每一个人的心愿。在此,我向全体同学提出以下建议,让我们行动起来,为安全而努力,让安全与我们同行。同学们,生命只有一次、健康不能重来。生命安全就掌握在我们自己手中。安全不仅关系我们个人、更关系到我们身后的家庭、学校、整个社会和整个国家。珍爱生命,增强安全意识,让快乐与幸福伴随我们的童年。今天我与同学们一起交流几个方面的安全问题。一、交通安全1、要遵守交通法规,基本常识有:行人靠右行,不闯红灯,不跨越护栏,横穿公路时要左顾右盼看是否有车辆经过,不脱把骑车,不骑“英雄”车,不跳车,不扒车。2、十二周岁以下的学生不准骑自行车。3、不乘坐黑车,因为黑车是“三无”车,有诸多不安全系数,出了安全问题,费用难以保证,更谈不上赔偿。
2、了解测量在生活中的应用,激发幼儿参与测量的兴趣。3、愿意与同伴合作交流,解决问题。活动准备:1、幼儿已有初步的测量经验。2、尺子、绳子、软尺、吸管、小棒、短积木、铅笔、筷子、纸卡段、盒子、书等物品。3、记录表、水彩笔、磁性板。活动过程:一、引题:提出任务今天小朋友来当“小小测量员”,用三种不同的工具来测量相同的一条边,并把测量结果记录下来。
友爱,是温暖的火苗,融化了人与人之间的冰冷;友爱,是甘甜的清泉,滋润着人与人之间的心灵;友爱,是和谐的纽带,联系着人与人时间的温情。有了它,班级才能像一个家,一个温暖的家,一个充满爱的家。在我们的班级生活中,其实处处见友爱:当同学摔倒,我们帮忙搀扶,这就是友爱;当同学的成绩在下降时,我们主动帮助,这就是友爱;当同学忘带了文具,我们大方借给他,这也是友爱……不过,在我们校园生活中,也时常有一些不和谐事情的发生。多半都是为了些小矛盾而产生纠纷,大家有时明明知道是谁对谁错,可彼此为了面子都不愿拉下赔礼道歉的脸。有时小小的冲动,会带来不小的麻烦!近年来,校园暴力事件在网上频频出现,这些冲动与暴力给自己与他人都带来了无法挽回的伤痛。这些,都在向我们警示:友爱的可贵。
结合历史自古以来,江山美人历来都是引无数英雄豪杰竞折腰的,如果说英雄选择了美人却丢了江山,把所有罪名都归结于“女人是祸水”。但是,纣王无道,和有了妲己有必然的联系吗?有人说妲己坏透了,坏透了的妲己如果不是取得纣王的信任是坏不起来的,纣王听信了妲己的谗言,听与不听决定权在纣王,而不在妲己。强势永远在纣王一边。再来看看西施和杨贵妃:西施是作为越国贡献给吴国的供品来到吴王夫差的身边的,杨贵妃更是先是李隆基的儿媳妇被看中而得宠的。所以,西施和杨贵妃这两个可怜的女人根本没有自己的独立选择,没有独立的爱情,如果没有西施,就会有南施,或北施;如果没有杨贵妃,就会有李贵妃,王贵妃,总之什么施,什么妃是不能少的,因为那是吴王和李隆基的需要。
This theme of the part is “ Describe people or things in greater detail”. Students have learned the grammar(restrictive relative clauses) in Book 1, and further review and consolidate its structure “prep+relative pronouns(which/whom)” and the relative adverbs(when, where and why), besides students should understand its form, meaning and functions. In this section, students should be able to express the grammar correctly in daily communication and in the writing. 1. Review the basic usages of relative pronouns and adverbs of attributive clauses . 2. Learn to use some special cases about restrictive relative clauses.3. Learn to write sentences with restrictive relative clauses flexibly according to the context.1. Review the basic usages of relative pronouns and adverbs of attributive clauses .2. Learn to use some special cases about restrictive relative clauses.3. Learn tow rite sentences with restrictive relative clauses flexibly according to the context.Step 1. Observe the following sentences, and mark the relative pronouns and the adverbs. 1. After listening to the scientists who had studied the problems, and citizens who lived near the dam, the government turned to the United Nations for help.2. Temples and other cultural sites were taken down piece by piece, and then moved and put back together again in a place where they were safe from the water.Step 2 PracticePlease complete these sentences with relative pronouns and relative adverbs and answer the following questions.Questions: 1. What is the head noun ?2. What relative words should be used ?3. What elements do they act in these sentences ?
This lesson aims at making a poster about protecting wildlife after reading some posters. During reading students are guided to understand the content and try to summarize the posters with one sentence. Then students are guided to try to make a poster about protecting wildlife.1. Read the two posters and try to understand the summary sentences.2. Look at the two posters and try to understand what emotions they express.3. Try to summarize the features of posters4. Try to make a poster about wildlife.1. Look at the two posters and try to understand what emotions they express.2. Try to summarize the features of posters3. Try to make a poster about wildlife.Step 1 Lead inLook at the the posters on the textbook and ask:Which emotions do the posters communicate ?Step 2 Read the poster and answer the questions.1. What do you think of the animals in the poster on the left ?I think it is frightening and ugly.2. Why do we should protect the ugly animals ?All species--the good, the bad, and the ugly-- should be treated equally.The world needs all kinds--without variety, our planet cannot survive.3. Why are billions of trees being cut down every year ?To make paper for humans.4. What result will be lead to after the trees are cut down ?A lost of animal homes are being destroyed./The habitat of wildlife is being destroyed.Step 3 Find the feature of posters1. What does each poster use to stir up emotions ?On the left, it makes us a little frightened and it looks a little ugly, but it can activate our curiosity--What is it? And What is wrong with it?On the right, it makes us feel a little sad and want to protect them.
1. This section focuses on "Understanding how a problem was solved”, which is aimed to guide students to analyze and discuss the challenges and problems faced by cultural heritage protection during the construction of Aswan Dam, as well as the solutions. On the basis of understanding, students should pay attention to the key role of international cooperation in solving problems, and attach importance to the balance and coordination between cultural heritage protection and social and economic development. Students are encouraged to face challenges actively, be good at cooperation, and make continuous efforts to find reasonable ways and means to solve problems.2. Enable students to understand the main information and text structure of the reading text;3. Motivate students to use the reading strategy "make a timeline" according to the appropriate text genre;4. Enable students to understand how a problem was solved;5. Enable students to understand the value of protecting cultural heritage by teamwork and global community;1. Guide students to pay attention to reading strategies, such as prediction, self-questioning and scanning.2. Help students sort out the topic language about protecting cultural relics and understand the narrative characteristics of "time-event" in illustrative style3. Lead students to understand the value of protecting cultural heritage by teamwork and global community;
2.表示现阶段正在进行的被动动作(该动作在说话的瞬间未必正在进行)。Many interesting experiments are being carried out these days.(说话时,并不一定正在进行)3.表示一种经常性的被动行为,常和always,constantly 等表示频度的副词连用,这种用法常常带有赞扬或厌恶的感情色彩。He is always being praised by the leader.4.表示按计划或安排主语将要承受谓语动词所表示的动作(仅限于少数及物动词)。A party is being held tonight.Step 4 Special cases1.像take care of, look after, talk about, think of等动词与介词构成的短语用于现在进行时的被动语态时, 其中的介词不可省略。The ways to stop illegally hunting are being talked about. 2.可与部分情态动词连用,表示对正在发生的事情的推测。She may be being punished by her mother.3.有时可表示按计划或安排将要进行的一个被动动作。A celebration is being held this weekend for his success.4.某些表示“状态、心理活动、存在”等的动词,如have,want,need,love,一般不用现在进行时的被动语态,而常用一般现在时的被动语态。With the population increasing,more land is needed.5.“be+under/in+n.”可表示现在进行时的被动意义。My computer is under repair.=My computer is being repaired.
The theme of this unit is human and nature, focusing on the theme of wildlife protection. Nature is a complex ecosystem, in which there are delicate balance between animals and plants. Because of the role of the food chain, the extinction of one species will produce influence, causing a series of chain reaction. Large scale extinction of species will have a serious and even irreversible impact on the ecosystem, resulting in immeasurable losses. Therefore, it is of great significance to protect wild species. To protect wild species is to protect human beings themselves. The motto of this unit is "when the buying stops, the killing can too,” which is a public service advertising slogan to protect wildlife. It tells people that every rhinoceros horn, every fur, every bowl of shark fin soup, every Ivory product, and every tiger bone product, etc. consumed by human beings, are innocent wild animals slaughtered behind them. The mission of wild aid is to ban illegal trade in endangered wildlife and mitigate climate change. It aims to educate the public to reduce the consumption demand for endangered wildlife products through public publicity and improve the awareness of environmental protection.1. Improve the awareness of wildlife protection by acquiring the knowledge of wildlife protection.2. Focus on environmental protection and protection of all lives.3. Analysis of the living environment of wild animals with appropriate thinking mode.4. Skillfully use the vocabulary and grammar knowledge of this unit to cultivate self-study ability according to the unit content5. Develop cooperative learning ability through discussion and other ways1. Enable the Ss to talk about the current situation of wild animals.2. Guide the Ss to summarize the main idea of each paragraph as well as the main idea of the text.
This teaching period mainly deals with grammar “The Present Perfect Passive Voice.” To begin with, teachers should lead students to revise what they have learned about the Present Perfect Passive Voice. And then, teachers move on to stress more special cases concerning this grammar。This period carries considerable significance to the cultivation of students’ writing competence and lays a solid foundation for the basic appreciation of language beauty. The teacher is expected to enable students to master this period thoroughly and consolidate the knowledge by doing some exercises. 1. Guide students to review the basic usages of the Present Perfect Passive Voice2. Lead students to learn to use some special cases concerning the Present Perfect Passive Voice flexibly.2. Enable students to use the basic phrases structures flexibly.3. Strengthen students’ great interest in grammar learning.1. Help students to appreciate the function of the Present Perfect Passive Voice in a sentence2. Instruct students to write essays using the proper the Present Perfect Passive Voice.观察下列句子特点,总结共同点。1.(教材P28)Much has been written about the wonders of the World Wide Web.2.(教材P28)But the Internet has done much more for people than simply make life more convenient.3.(教材P28)Many people have been helped by the club.4.(教材P28)She no longer feels lonely, and her company has become quite successful.5.(教材P32)Today I thought I’d blog about a question that has been asked many times—how do you stay safe online and avoid bad experiences on the Internet?
PPT全称是PowerPoint,LFPPT为你提供免费PPT模板下载资源。让你10秒轻松搞定幻灯片制作,打造⾼颜值的丰富演示文稿素材模版合集。