1.3 本册综合 学案(冀教版八年级上册)
1.2本册综合教案(冀教版八年级上册)
Unit12 What’s the best radio station? Ⅰ.Teaching aims and demands:Students learn to make comparisons and discuss preferences.Ⅱ.Key and difficult points:A. Vocabulary1. theater, cinema2. trendy, quality, comfortable, close to3. seat, screen, jeans, performer, radio station4. new, big, friendly, fun, boring, popular, cheap, service, creative,clothes, clothing, store, music, piano, actor, music video, TV showB. Target language1. What’s the best cinema? Showtime Cinema. It’s the cheapest.2. Jason’s has good quality clothes.It’s better than Trendy Teens. Jason’s is the best store in town.C. StructuresSuperlatives with –(i)est, the mostIrregular comparisons:good, better, the best, bad, worse, the worstD. GrammarThe superlative degree of adjectives.Ⅲ.Teaching aids :A tape recorderⅣ.Teaching methods:Audio-lingual method; Communicative Approach;Ⅴ.This unit is divided into five periods.Period 1 Listen and speakⅠ.Teaching aims and demands:Students learn to make comparisons and discuss preferences.Ⅱ.Key and difficult points:A. Vocabulary1. popular, comfortable, worse, worst, biggest, closest, friendliest,funniest, cheap, cheapest, pretty bad2. service, clothing store, radio station, part, price, screen, seatB. Target language1 What’s the best cinema? Showtime Cinema. It’s the cheapest.2 Jason’s has good quality clothes.It’s better than Trendy Teens. Jason’s is the best store in town.C. StructuresSuperlatives with –least, the mostIrregular comparisons good, better, the best, bad, worse, the worstD. GrammarThe superlative degree of adjectives.Ⅲ.Teaching aids :A tape recorderⅣ.Teaching methods:Audio-lingual method; Communicative Approach; PPPⅤ.Teaching procedures:Step 1Warming upTask 1 Ask students about the stores they like to go to. Write the names of these places on the board.Task 2 Help students compare the three stores using the words good, better, and best.T: Where do you buy CDs?S1: I buy CDs at Great Records and New Music.T: Does Great Records have good CDs?S2: I think New Music has better CDs.T: Who has the best CDs?S3: The Music Mega Store.Step 2Key vocabularyTask 1 Read the instructions.Task 2 Read each item to the class. Ask the students to explain what the word or phrase means in their own words.Task3 Ask students to decide which of the things are important and which are not important. Write their answers.Task4. Find out which items students think are most important.Step 3Target languageTask 1 Read the instructions.Task 2 Point to the chart. Explain the meaning of any phrases students don’t know.Task 3 Point to the list of Movie theaters in the instructions and the blank lines under the Movie theater heading.Task 4 Play the recording the first time. Students only listen.Task 5 Play again. Ask students to write the names of each movie theater on the blank line.Task 6 Check the answers.Step 4Pair workTask 1 Ask students to look at the pictures in activity 1a. Then ask students to read the sample conversations in activity 1c.Task 2 Ask students to read the instructions to the class .Task 3 Ask students to work in pairs and make their own conversations about the movie theater in the picture.Task 4 Ask some pairs to present one or more of their conversations to the class.Ⅵ Homework1 Remember the vocabulary and the target language.2 Review the superlative degree of adjectives.NotePeriod 2 Listen , speak and Grammar Focus Ⅰ.Teaching aims and demands:1. Revise the target language, and complete the listening practice;2. Learn Grammar Focus.Ⅱ.Key and difficult points:A. Vocabulary1. jeans , trendy, funky2.radio, FM(=Frequency Modulation),AM(=Amplitude Modulation)B. Target language1. I’m a reporter. Can I ask you some questions? Sure.2. What’s the best clothing store in town? I think Jason’s is the best.3. Why do you think so? Jason’s has...C. StructuresSuperlatives with –least, the mostIrregular comparisons good, better, the best, bad, worse, the worstD. GrammarThe superlative degree of adjectives.Ⅲ.Teaching aids :A tape recorderⅣ.Teaching methods:Audio-lingual method; Communicative Approach;Ⅴ.Teaching procedures:Step 1RevisionTask 1 Revise the usage of the superlative degree by asking the following questions:Who is the tallest boy in our class?Who is the tallest girl in our class?Who is the busiest student in our class?Who is the best student in our class?Task 2 Practice the conversations using the target language students have already studied.Step 2ListeningTask 1 Read the instructions and point to the two questions on the survey.Task 2 Ask some students to read the names of the stores and the radio stations.Task 3 Play the recording the first time. Students only listen.Task 4 Play again. Ask students to circle the letters of the correct answers.Task 5 Check the answers.Step 3ListeningTask 1 Read the instructions and point to the chart. And read the names of the stores and comments after each one or ask differentstudents to do it.Task 2 Play again. Ask students to circle the correct words the boy says.Task 3 Check the answers.Step 4Pair workTask 1 Read the instructions for the activity.Task 2 Ask students to read the sample conversations.Task 3 Ask students to say some of the questions the reporter asked the boy. Write the questions on the board.Task 4 Ask students to work in pairs, ask and answer,Task 5 Ask one or two pairs to say their conversations to the class.Step 5 Grammar FocusTask 1 Read Grammar FocusTask 2 Emphasize: cheapest, friendliest, most comfortableGood—better—best , bad—worse—worstⅥ Homework1. Revise the target language.2. Finish off the exercises on work book.3. Write a department survey about your city,find out which one isthe best shop.NotePeriod 3 Read and speakⅠ.Teaching aims and demands:1 Revise the target language, and complete the reading practice;2 Go on learning the superlative degree of adjectives.Ⅱ.Key and difficult points:A. Vocabulary1. teen (=teenager), bargain, delight, by bus,2. best, worst, cheapest, most expensiveB. Target language1. I think Teen World has the best service.2..All the movie theaters are good, but the Screen City is the best inour town.3. The most popular clothing store is Jason’s.C. StructuresSuperlatives with –least, the mostIrregular comparisons good, better, the best, bad, worse, the worstD. GrammarThe superlative degree of adjectives.Ⅲ.Teaching aids :A tape recorderⅣ.Teaching methods:Audio-lingual method; Communicative Approach; Control readingⅤ.Teaching procedures:Step 1RevisionTask 1 Dictation: words and expressions.Task 2 Revise the Grammar Focus.Step 2ReadingTask 1 Read the directions.Task 2 Ask students to read the article on their own, and circle the words and phrases they don’t understand.Task 3 Ask students to read the words and phrases they don’t understand, ask other students to explain.Task 4 Ask students to read again and complete the chart.Task 5 Check the answers.Step 3 Writing and speakingTask 1 Read the directions.Task 2 Ask students to say the names of stores in your town and write the names on the board.Task 3 Ask students to work with partners as they talk about the stores and fill in the chart.Task 4 Ask the two or three pairs of students who finish first to put their charts on board.Step 4Group work Where are we going for lunch?Task 1 Ask the class for the names of three places to have lunch near the school and write them on the board. And elicit answers forone of the restaurants.Task 2 Divide the class into small groups. Ask them to choose three restaurants and fill in the chart.Task 3 Ask the groups which restaurant they decided on. Why did they decide on that restaurant.Ⅵ Homework1 Revise the target language.2 Finish off the exercises on work book.NotePeriod 4 Section BⅠ.Teaching aims and demands:1. Learn some new language.2. Complete the listening practice;Ⅱ.Key and difficult points:A. New languagefunniest, most creative, quietest, dullest, loudest, saddest, cute,music video, musical group, performer, song, success, talent showB. StructuresSuperlatives with –(i)est, the mostIrregular comparisons good, better, the best, bad, worse, the worstC. GrammarThe superlative degree of adjectives.Ⅲ.Teaching aids :A tape recorderⅣ.Teaching methods:Audio-lingual method; Communicative Approach; PPPⅤ.Teaching procedures:Step 1 DiscussionTask 1 Discuss with the Ss about their characters, list out the words on the blackboard to help the Ss describe their characters.creative, honest, loyal, wise, kind, smart, funny, brave, quiet, dull, loud, worst, boring, stupid, noisyTask 2 Practice the conversations using the target language students have already studied.Step 2 New wordsTask 1 Read the instructions.Task 2 Ask students to complete activity 1a on their own.Task 3 Correct the answers.Step 3Pair workTask 1 Read the instructions and read the sample sentences to the class.Task 2 Ask students to work in pairs to discuss their answers in activity 1a.Task 3 Ask several pairs to say their sentences to the class.Step 4 ListeningTask 1 Read the instructions.Task 2 Point to the five pictures. Ask different students to say what the people are doing in the picture.Task 3 Ask a student to read five names.Task 3 Play the recording the first time. Students only listen.Task 4 Play again. Ask students to correct name under each picture. .Task 5 Check the answers.Step 5 ListeningTask 1 Read the instructions and point to the chart.Task 2 Ask a student to read the first line of the chart.Task 3 Play again. Ask students to write what different people say about the performers.Task 4 Check the answers.Step 6Pair workTask 1 Read the instructions for the activity.Task 2 Ask students to look at the information about the talent show.Task 3 Ask students to work in pairs.Task 4 Ask several pairs to say different questions and answers to the class .Step 7WritingTask 1 Ask a student to read the beginning of the article.Task 2 Ask students to say the names of famous performers they might write about. Ask them what words they could use to describeeach performer.Task 3 Ask students to write their articles on their own.Task 4 Ask some students to read their articles to the class.Step 8Pair workTask 1 Read the instructions.Task 2 Ask two students to read the sample conversations to the class.Task 3 Ask students to interview each other.Task 4 Ask some students to perform to the class.Step9Self checkTask 1 Fill in the blanks.Task 2 Read the information about the three cities and describe which is the best city to visit for a winter vacation..Task 3 Just for fun: read and act out.Ⅵ Homework1 Revise the target language.2 Finish off the exercises on work book。
冀教版八年级上册语文全册教案
备课本冀教版八年级上册语文全册教案班级______教师______日期______冀教版八年级上册语文全册教案教师_______日期_______1、故乡一、教学重点1.学习本文用生动的肖像描写和对比方法刻画人物、突出中心的写法。
2.了解本文以“我”回故乡的见闻感受为线索安排情节的方法。
3.理解鲁迅先生通过写回故乡的一段经历,揭示的人与人之间的可悲隔膜,表达了自己渴望改变现实、渴望新生活的强烈愿望。
二、教学难点1.以中心事件为线索结构文章。
2.最后三个自然段的深刻含义。
三、知识点1.“教学重点”1、2所列内容。
2.景物描写的作用。
3.比喻、借代等修辞方法。
4.生字、生词。
四、教学过程1.导入新课,简介背景。
1919年12月,鲁迅从北京回故乡绍兴搬家,亲眼看到离别多年的故乡破败不堪,农民生活十分穷困,百感交集,思绪万千,一年后便以这段经历为素材,写下了这篇小说。
写的是辛亥革命后,封建王朝的专制政权是被推翻了,但代之而起的是地主阶级的军阀官僚的统治。
帝国主义不但操纵了中国的财政和经济的命脉,而且操纵了中国的政治和军事力量。
由于这双重的压迫,中国的广大人民,尤其是农民,日益贫困化,他们过着饥寒交迫的和毫无政治权利的生活。
小说写于1921年1月,后作者又编入他的小说集《呐喊》,它的故事情节和主要人物,大多取材于真正的现实生活。
小说以“我”回故乡的见闻感受为线索,着重刻画了一个受尽当时社会摧残剥削的劳苦农民闰土的形象。
通过对闰土悲惨遭遇的描述,生动地反映了当时的社会面貌,深刻揭露旧社会对农民从肉体到精神的重重残害,表达了作者改造旧社会、创造新生活的强烈愿望和坚定信念。
鲁迅,我国现代伟大的文学家、思想家、革命家。
原名周树人,字豫才,鲁迅是笔名,浙江绍兴人。
选自《呐喊》(小说集)。
(《百草园》选自散文集《朝花夕拾》。
练习:本文选自________,作者________,原名________,浙江________人,我国伟大的________家、________家、________家。
(冀教版)数学八年级上册精品导学案 (全书完整版)
(冀教版)八年级数学上册(全册)精品导学案汇总反证法学习目标:1.了解反证法的意义及用反证法证明一个命题是真命题的一般步骤.2.学会运用反证法证明有关命题.学习重点:反证法的一般步骤.学习难点:运用反证法证明有关命题.自主学习知识链接1.在证明一些命题是真命题时,一般采用__________证明的方法.2.在证明与图形有关的命题时,一般有哪些步骤?答:第一步_________________________________________________________ 第二步_________________________________________________________第三步_________________________________________________________预习新知除了直接证明的方法,还有_________证明的方法,_________法就是常用的间接证明方法.在证明一个命题时,有时先假设命题的________不正确,然后从这个___________出发,经过逐步_______________,最后推出与___________、__________、____________相矛盾的结果,从而得出________是错误的,__________正确的.这种证明命题的方法叫做反证法.用反证法证明一个命题是真明题的一般步骤是:第一步_________________________________________________________第二步_________________________________________________________第三步_________________________________________________________自学自测1.写出下列各结论的反面:(1)a//b;(2)a≥0;(3)b是正数;(4)有且只有一个交点;(5)一个三角形中最多有一个直角; (6)a ,b 中至少有一个等于0.2.求证:在同一平面内,如果一条直线和两条平行直线中的一条相交,那么和另一条也相交. 已知:如图,a ∥b ,c 与a 相交于点P 求证: c 与b 相交四、我的疑惑_____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________要点探究探究点:用反证法证明有关命题例1.试证明命题“三角形中最多有一个角是直角”.【归纳总结】若结论的反面不止一种情况,必须把各种可能情况全部列举出来,并逐一加以否定,才能肯定原结论是正确的. 【针对训练】试证明:在一个三角形中,至少有一个内角小于或等于60°.已知: . 求证: .证明:假设 ,则 .合作探究a bcP21H F G EDC B A ∴ . 即 .这与 矛盾.假设不成立. ∴ .例2.试证明:如果两条直线都与第三条直线平行,那么这两条直线也平行.已知: . 求证: .证明:假设 ,则可设它们相交于点A.那么过点A 就有 条直线与直线c 平行,这与“过直线外一点 ”矛盾. ∴假设不成立.∴ .【归纳总结】在推理论证时,要把新增的已知条件(即假设的内容)加进去,然后逐步推出与已知公理或定理之间的矛盾. 【针对训练】用反证法证明平行线的性质定理一: . 已知:如图,直线AB ∥CD ,直线EF 分别与直线AB 、CD 交于点G 、H ,∠1和∠2是同位角. 求证:∠1=∠2.例3.如图,在△ABC 中,AB=AC ,P 是△ABC 内的一点,且∠APB >∠APC ,求证:PB <PC (反证法)【归纳总结】反证法主要用于直接证明比较困难的命题.如结论以否定形式出现的命题,唯一性命题,结论含有“至少”“至多”等词.【针对训练】如图,在△ABC中,AB>AC,AD是内角平分线,AM是BC边上的中线,求证:点M不与点D 重合二、课堂小结反证法的意义反证法反证法的一般步骤用反证法证明有关命题当堂检测1.用反证法证明“在一个三角形中,至少有一个内角大于或等于60°”时第一步应先假设()A.每一个内角都小于60°B.至多有一个内角小于60°C.每一个内角大于或等于60°D.至多有一个内角小于或等于60°2.在证明“在△ABC中至少有一个角是直角和钝角”时,第一步应假设()A.三角形至少有一个角是直角或钝角B.三角形中至少有两个直角或钝角C.三角形中没有直角或钝角D.三角形中三个角都是直角或钝角3.反证法证明命题“同旁内角不互补的两条直线不平行”时,应先假设 .4.已知直线m、n是相交线,且直线l1⊥m,直线l2⊥n.求证:直线l1与l2必相交.5.已知a2=5,证明:a是无理数.6.如图,在△ABC中,D、E分别是AC、AB上的中点,且BD≠CE,求证:AB≠AC直角三角形全等的判定学习目标:1.理解直角三角形全等的判定方法“HL”,会用“HL”判定两个直角三角形全等.2.理解角平分线性质定理的逆定理.学习重点:理解直角三角形全等的判定方法“HL”.学习难点:“HL”的应用.自主学习知识链接1.勾股定理:如果直角三角形的两条直角边长分别为a,b,斜边长为c,那么2c=(或c=)变形:2a=(或a=),2b=(或b=)2.判定两个三角形全等的方法有:、、、二、新知预习1.动手试一试已知:两条线段(两条线段长度不相等),一条为2cm,一条为3cm.试着画出一个直角三角形,使3cm长的线段为三角形的斜边,2cm长的线段为其一条直角边.作法:(1)作一条线段CB,使它等于2cm;(2)过点C,作直线MC⊥CB;(3)以点B为圆心,3cm长为半径画圆弧,交射线CM于点A;(4)连接AB.△ABC即为所求2.将你画的三角形和同桌画的三角形进行比较,由此你能猜想到什么呢? 【结论】由上面的画图实验可以得到直角三角形全等的判定定理: 斜边和一直角边对应相等的两个直角三角形 (可以简写成“ ”或“ ”)3. 尝试证明以上结论 已知:如图,在Rt △ABC 和Rt '''A B C ∆中, ∠C=∠C’=90°,AB=A’B’,AC=A’C’ 求证:Rt △ABC ≌Rt '''A B C ∆ 【提示】先利用勾股定理证明另一条直角边相等,再用“SAS ”或“SSS ”证明这两个三角形全等 证明:自学自测 1.判断题:(1)一个锐角和这个锐角的对边对应相等的两个直角三角形全等( ) (2)一个锐角和锐角相邻的一直角边对应相等的两个直角三角形全等( ) (3)一个锐角与一斜边对应相等的两个直角三角形全等( ) (4)两直角边对应相等的两个直角三角形全等( ) (5)两边对应相等的两个直角三角形全等( ) (6)两锐角对应相等的两个直角三角形全等( )(7)一个锐角与一边对应相等的两个直角三角形全等( )(8)一直角边和斜边上的高对应相等的两个直角三角形全等( ) 2.如图,若要用“HL”证明Rt△ABC≌Rt△ABD,则还需补充条件( ) A .∠BAC=∠BAD B .AC=AD 或BC=BDC .AC=AD 且BC=BDD .以上都不正确四、我的疑惑_____________________________________________________________________________ _____________________________________________________________________________AB C A ’B ’C ’_____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________要点探究探究点:利用“HL ”判定两个直角三角形全等例1.如图,B 、E 、F 、C 在同一直线上,AF ⊥BC 于F ,DE ⊥BC 于E , AB=DC ,BE=CF ,你认为AB 平行于CD 吗?说说你的理由 解:AB 平行于CD理由:∵ AF ⊥BC ,DE ⊥BC (已知)∴ ∠AFB=∠DEC= °(垂直的定义) ∵BE=CF ,∴BF=CE在Rt △ 和Rt △ 中 ∵⎩⎨⎧==_______________________________∴ ≌( )∴ = ( ) ∴ (内错角相等,两直线平行) 【归纳总结】用“HL ”判定两个直角三角形全等时,要找到一组斜边和一组直角边对应相等. 【针对训练】求证:有一条直角边及斜边上的高对应相等的两个直角三角形全等.例2.请写出角平分线的性质定理的逆命题,并判断该命题的真假.【归纳总结】通过做辅助线构造两个全等的直角三角形,也是证明线段相等的常用方法. 【针对训练】如图:AB=AD ,∠ABC=∠ADC=90°,EF 过点C ,BE ⊥EF 于E ,DF ⊥EF 于F ,BE=DF .合作探究求证:Rt△BCE≌Rt △DCF二、课堂小结内容直角三角形全等的判定定理和对应相等的两个直角三角形全等.(可以简写成“”或“”)角平分线性质定理的逆定理定理到距离相等的点在这个角的平分线上.1.判断两个直角三角形全等的方法不正确的有()A.两条直角边对应相等 B.斜边和一锐角对应相等C.斜边和一条直角边对应相等 D.两个锐角对应相等2.如图,∠A=∠D=90°,再添加一个条件,即可使Rt△ABC≌Rt△DCB,理由是.3.如图,∠B=∠D=90°,BC=DC,∠1=40°,则∠2= .4.如图所示,已知在△ABC中,∠C=90°,AD=AC,DE⊥AB交BC于点E,若∠B=28°,则∠AEC=()A.28°B.59°C.60 D.62°5.如图,有两个长度相同的滑梯,左边滑梯的高度AC与右边滑梯水平方向的长度DF相等,两个滑梯的倾斜角∠ABC和∠DFE的大小有什么关系?当堂检测6.如图,公路上A、B两站相距25km,在公路AB附近有C、D两学校,DA⊥AB 于点A ,CB ⊥AB于点B.已知DA=15km,CB=10km,现要在公路上建设一个青少年活动中心E,要使得C、D两学校到E的距离相等,则E应建在距A多远处?勾股定理第2课时勾股定理的应用学习目标:1.能熟练运用勾股定理计算.2.会用勾股定理解决简单的实际问题.学习重点:用勾股定理解决实际问题.学习难点:勾股定理的熟练运用.自主学习知识链接1. 勾股定理:如果直角三角形的两条直角边长分别为a,b,斜边长为c,那么2c=(或c=)变形:2a=(或a=),2b=(或b=)2.填空题:在Rt△ABC,∠C=90°,⑴如果a=7,c=25,则b= ;⑵如果∠A=30°,a=4,则b= ;⑶如果∠A=45°,a=3,则c= ;(4)如果b=8,a:c=3:5,则c= .二、新知预习如图,一个3m长的梯子AB,斜靠在一竖直的墙AO上,这时AO的距离为2.5 m,如果梯子的顶端A沿墙下滑0.5m,那么梯子底端B也外移0.5 m吗?提示:梯子底端B随着梯子顶端A沿墙下滑而外移到D,那么的长度就是梯子外移的距离.②BD=-,求BD,关键是要求出和的长.③梯子在下滑的过程中,梯子的长度变了吗?④在Rt△AOB中,已知和,如何求OB?在Rt△COD中,已知和,如何求OD?自学自测1.小军量得家里新购置的彩电荧光屏的长为58厘米,宽为46厘米,则这台电视机的尺寸是(实际测量的误差可不计)()A.9英寸(23厘米)B.21英寸(54厘米)C.29英寸(74厘米)D.34英寸(87厘米)2.如图所示:是一段楼梯,高BC是3m,斜边AC是5m,如果在楼梯上铺地毯,那么至少需要地毯m.四、我的疑惑_____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________合作探究要点探究探究点:勾股定理的实际应用例1.如图,有两棵树,一棵高10米,另一棵高4米,两树相距8米,一只小鸟从一棵树的树梢飞到另一棵树的树梢,问小鸟至少飞行多少米?【归纳总结】解题关键是利用转化思想将实际问题转化成直角三角形模型,然后利用勾股定理求出未知的边长.【针对训练】如图,一根12米高的电线杆两侧各用15米的铁丝固定,两个固定点AB之间的距离是()A.13 B.9 C.18 D.10例2.一个门框的尺寸如图所示,一块长3m,宽2.2m的薄木板能否从门框内通过?为什么? 思考:①薄木板怎样好通过?;②在长方形ABCD中,是斜着能通过的最大长度;③薄模板能否通过,关键是比较与的大小.解:在Rt△ABC中,根据勾股定理AC2=()2+()2=2+2=.因此AC=≈.因为AC(填“>”、“<”、或“=”)木板的宽2.2m,所以木板从门框内通过.(填“能”或“不能”)【归纳总结】根据门框的尺寸,可以求出能通过此门框的薄木板的最大宽度,然后与之作比较【针对训练】小东拿着一根长竹竿进一个宽3米的城门,他先横着拿进不去,又竖起来拿,结果竿比城门高1米,当他把竿斜着时,两端正好顶着城门的对角,问竿长几米?二、课堂小结利用勾股定理求长度勾股定理的应用利用勾股定理解决实际问题当堂检测1.现有两根木棒的长度分别是40cm和50cm,若要钉成一个直角三角形框架,那么可以选用的木棒是()A.30cm B.40cm C.50cm D.60cm2.如图,在5×5的正方形网格中,下列数据与线段AB长最接近的是()A.4 B.5 C.6 D.73.小明用火柴棒摆直角三角形,已知他摆两条直角边分别用了6根和8根火柴棒,他摆完这个直角三角形共用火柴棒()A.20根B.14根C.24根D.30根4.一架2.5m长的梯子斜靠在一竖直的墙上,这时梯脚距离墙角0.7米,如果梯子的顶端沿墙下滑0.4米,那么梯脚移动的距离是()A.0.4m B.0.9m C.0.8m D.1.8m5.如图,能否将一根70㎝长的细木棒放入长、宽、高分别为40cm、30cm、50cm的长方体盒子中?勾股定理第1课时 勾股定理 学习目标:1.掌握勾股定理,能用拼图的方法验证勾股定理.2.会用勾股定理解决简单的问题. 学习重点:勾股定理.学习难点:勾股定理的验证.知识链接如果一个正方形的边长是a ,那么它的面积是 .2.如果一个直角三角形的两直角边分别为a ,b ,那么它的面积是 . 新知预习1.下图是用大小相同的两种颜色的正方形瓷砖铺成的地面.(1)图(1)中用白色框标出的三个正方形,他们的面积之间具有怎样的等量关系?(2)根据图(2),你能说出正方形面积之间的等量关系反映了Rt ∆ABC 三边之间怎样的关系吗?把它写出来.(3)如图(3),∆ABC 是直角三角形,∠ACB=90°.如果每个小方格子都是边长为1的正方形,那么Rt ∆ABC 的三边AC,BC,AB 的长各是多少?以AC,BC,AB 为边的三个正方形的面积各是多少?这些面积之间具有怎样的等量关系?对于更一般的情形,如果这个直角三角形的三边长分别是a ,b ,c ,那么可以怎样用a ,b ,c 把图中三个正方形面积之间的关系表示出来呢?自主学习图(1)A BC图(2) ACB acb 图(3)本实验的结论如何用文字语言加以叙述?4.如图是用四个全等的直角三角形拼成的,请根据此图验证你所得到的结论. 【提示】:用两种方法表示出大正方形的面积.【归纳总结】勾股定理:如果直角三角形的两条直角边长分别为a ,b ,斜边长为c ,那么 . 自学自测1.图中已知数据表示面积,求表示面积的未知数1s、2s 的值.2.图中已知数据表示边长,求表示边长的未知数1x 、2x 的值.四、我的疑惑_____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________要点探究探究点1:勾股定理的验证例1.比较图中两个正方形的面积,并验证勾股定理.【归纳总结】利用面积验证勾股定理,即从两个不同角度看一个图形的面积,建立含直角三角形三边的等式得到a 2+b 2=c 2. 【针对训练】如图是由三个直角三角形组成的直角梯形,请证明a 2+b 2=c 2.探究点2:利用勾股定理求值例2.如图,已知在Rt △ABC 中,∠C =90, (1)若5,12,a b 则c === ; (2)若10,8,c b a 则=== ; (3)若25,24,c a b ===则 . (4)若35a :=:c ,2b =a =则 ,c = .【归纳总结】由勾股定理的基本关系式a 2+b 2=c 2,还可以得到一些变形式.如:222222,a c b b c a c a b =-=-=+,.【针对训练】若直角三角形的两边长分别为3cm 、4cm ,则第三边长为 .二、课堂小结合作探究b c a c ABDC勾股定理的推导及验证勾股定理利用勾股定理求值1.若一个直角三角形的三边长为8,15,x ,则x = . 2.如图,学校有一块长方形花圃,有极少数人为了避开拐角 走“捷径”,在花圃内走出了一条“路”.他们仅仅少走了 步路(假设2步为1m ),却踩伤了花草.3.如图,分别以Rt △ABC 的三边为直径作半圆,其面积分别为1S 、2S 、3S ,且15S =,212S =,则3S = .直线同侧有三个正方形a 、b 、c ,若a 、c 的 面积分别为5和12,则b 的面积为 .5.已知:如图,等边△ABC 的边长是6cm. ⑴求等边△ABC 的高. ⑵求S △ABC .勾股定理第3课时 勾股定理的逆定理及其应用 学习目标:1.掌握勾股定理的逆定理.2.会利用勾股定理的逆定理判断直角三角形及解决实际问题. 学习重点:勾股定理的逆定理.学习难点:勾股定理的逆定理的应用.当堂检测知识链接1. 勾股定理:如果直角三角形的两条直角边长分别为a ,b ,斜边长为c ,那么 .文字叙述: 2.写出下列命题的逆命题:(1)同位角相等,两直线平行.它的逆命题是: (2)如果天空在下雨,那么地面是湿的.它的逆命题是: (3)对顶角相等.它的逆命题是: 新知预习1.画图:画出边长分别是下列各组数的三角形(单位:厘米) A.3、4、3 ; B.3、4、5; C.3、4、6;D.6、8、102.测量:用你的量角器分别测量一下上述各三角形的最大角的度数,并记录如下: A._______ B._______ C.______ D.______3.判断:请判断一下上述你所画的三角形的形状. A.______ B._______ C.______ D.______4.找规律:根据上述每个三角形所给的各组边长请你找出最长边的平方与其他两边的平方和之间的关系. A.______ B._______ C.______ D.______猜想:一个三角形各边长数量应满足怎样的关系时,这个三角形才可能是直角三角形呢?(1)结论:如果一个三角形的三条边长a 、b 、c 满足 ,那么这个三角形是直角三角形. (2)由于以上结论是勾股定理的 命题,所以我们把这个结论叫做 . 自学自测1.判断由a 、b 、c 组成的三角形是否是直角三角形:(1)a =15,b =8,c =17 (2)a =13,b =14,c =15 (3)a =41,b =4,c =5 (4)a =45,b =1,c =43(5)a =0.5,b =1.2,c =1.3 (6) a =21,b =23,c =222.若一个三角形的三边之比为5∶12∶13,且周长为60cm ,则它的面积为 .四、我的疑惑_____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________要点探究探究点1:勾股定理的逆定理的证明 问题:试证明勾股定理的逆定理.【提示】 构造一个与该三角形全等的直角三角形.已知:如图,在△ABC 中,AB=a ,BC=b ,CA=c ,且______________. 求证:∠C=90°.证明: 作△A’B’C’,使A ’B ’=a ,B ’C ’=b ,∠____=_____°. 由勾股定理,可得_____________________________________________ _____________________________________________ ____________________________________________ ___________________________________________ ___________________________________________ ___________________________________________ ∴△ABC ≌△A’B’C’( _______ ) ∴∠____=∠_____=90°.探究点2:利用勾股定理的逆定理判断直角三角形例1.已知a ,b ,c 为△ABC 的三边,满足442222b ac b c a -=- ,试判断△ABC 的形状.合作探究【归纳总结】对已知条件进行等式变形,化简,看是否能得到222c b a =+ 【针对训练】已知ABC Δ的三边分别a ,b ,c ,其中a =22n m -,b =2mn ,c =22n m +(m>n ,m ,n 是正整数),ABC Δ是直角三角形吗?说明理由.例2.如图,∠C =90°,AC =3,BC =4,AD =12,BD =13,试判断△ABD 的形状,并说 明理由.【归纳总结】先求出该三角形的三边长,然后验证这三边是否满足勾股定理的逆定理. 【针对训练】如图,在正方形ABCD 中,F 为DC 的中点,E 为BC 上一点,且EC=14BC ,求证:AF ⊥EF .【提示】 要证AF ⊥EF ,只需证△AEF 是直角三角形.不防设正方形的边长为1(或x ),然后利用勾股定理分别求出AE ,EF ,AF 的长,最后进行验证.探究点3:勾股定理的逆定理的实际应用例3.“远航”号、“海天”号轮船同时离开港口,各自沿一固定方向航行,“远航”号每小时航行16海里,“海天”号每小时航行12海里. 它们离开港口一个半小时后相距30海里. 如果知道“远航”号沿东北方向航行,能知道“海天”号沿哪个方向航行吗?【归纳总结】先判断△OPR 为直角三角形,便可知道PR 的方向了.CB DA【针对训练】如图,一块四边形地ABCD ,已知AD=4m ,CD=3m ,∠ADC=90°,AB=13m ,BC=12m ,则这块地的面积为( )㎡.A .24B .30C .48D .60二、课堂小结勾股定理的逆定理:如果一个三角形的三条边长a 、b 、c 满 足 ,那么这个三角形是直角三角形. 勾股定理的逆定理及其应用勾股定理的逆定理的应用1.分别以下列四组数为一个三角形的边长:(1)3,4,5; (2)5,12,13; (3)8,15,17; (4)4,5,6. 其中能构成直角三角形的有( ) A .4组 B .3组 C .2组 D .1组2.三角形ABC 中,∠A,∠B,∠C 的对边分别是a,b,c,且 c+a=2b , c – a= b 21,则△ABC 的形状是 .3.△ABC 的三边长分别为 9 ,40 ,41 ,则△ABC 的面积为____;4.如图,在7×4的网格上有一个△ABC (A 、B 、C 分别在小正方形的顶点上).若每个小正方形的边长都为1,则△ABC 是( )A .锐角三角形B .钝角三角形C .直角三角形D .等腰三角形直角三角形学习目标:当堂检测1.理解直角三角形的定义及直角三角形的两个锐角互余这一性质.2.会用“两个锐角互余的三角形是直角三角形”这个判定方法判定直角三角形.3.理解并掌握“直角三角形斜边的中线等于斜边的一半”这一性质,并能灵活运用.4.理解并掌握“在直角三角形中,30°角所对的边等于斜边的一半”这一性质. 学习重点:直角三角形斜边的中线等于斜边的一半.学习难点:“在直角三角形中,30°角所对的边等于斜边的一半”的运用知识链接1.下面的图案都是由七巧板拼成的,你能从图中找出多少个直角三角形呢?三角形按内角的大小可分为 三角形、 三角形、 三角形. 三角形的内角和是 . 新知预习定义: 的三角形叫做直角三角形. 直角三角形可以用符号“Rt △”表示,例如,直角三角形ABC 可以表示成“ ”. 2.由于三角形的内角和是 °,直角三角形有一个角是 °,所以另外两个角的和是 °.于是有直角三角形的性质定理:直角三角形的两个锐角 . 3.试写出该定理的逆命题:如果 ,那么 . 4.上面的逆命题是 命题,于是有直角三角形的判定定理:有两个角 的三角形是直角三角形. 自学自测已知△ABC 中∠A :∠B :∠C=1:2:3,那么这个三角形是( )A.锐角三角形B.钝角三角形C.直角三角形D.等腰角三角形如图:在△ABC 中,∠ACB=90°,CD ⊥AB 于点D ,若∠A=40°, 则∠BCD=_____.3.如图,在△ABC 中,∠ACB =90º,CD 是∠ACB 的平分线,CE 是边AB 上的中线,CF 是边AB 上的高.求证:∠ECD =∠FCD .自主学习E FD CBAD BA四、我的疑惑_____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________要点探究探究点1:直角三角形的性质定理问题:在一张半透明纸上画出Rt △ABC ,∠C=90°;如图,将∠B 折叠,使点B 与点C 重合,折痕为ED ,连接CE .⑴∠ECD 与∠B 有怎样的关系?线段EC 与线段EB 有怎样的关系? ⑵∠ACE 与∠A 有怎样的关系?线段EC 与线段EA 有怎样的关系?⑶由此,你发现了什么结论?你能给出证明吗?试试看.已知:如图,在Rt △ABC , , . 求证: . 证明:【归纳总结】直角三角形的性质定理:直角三角形 等于 的一半. 例1.如图,AD 是Rt △ABC 斜边上中线,若BC=10,则AD= .【针对训练】合作探究E D CB ACB AAD是Rt△ABC斜边BC上中线,若AD+BC=15cm,则AD= ,CB= .探究点2:含30°角的直角三角形问题:在直角三角形中,如果有一个锐角等于30°,那么它所对的直角边与斜边有何关系?请说明理由.已知:在Rt△ABC中,∠C=90°,∠A=30°,求证:BC=12 AB.【归纳总结】在直角三角形中,所对的直角边等于斜边的一半.例2.如图,在Rt△ABC中,∠C=90°,∠A=30°,AB+BC=12cm,则AB等于 .例3.如图,在△ABC中,AB=AC,∠BAC=120°,DE⊥AB,且BE=AE.求证:DC=2BD.【归纳总结】“30°角”的性质常常用来证明线段的倍分关系,在含30°角的直角三角形中证明有关结论,有以下四种常见思路:(1)若题目中出现含30°或60°角的直角三角形,则可直接运用性质证明;(2)若题目中只出现30°或60°的角,则可通过作高等方法构造直角三角形;(3)若题目中出现15°或150°的角,则在三角形外作高线构造直角三角形;(4)若题目中出现90°和60°(或30°)的角,但没有出现三角形,则可通过延长边等方法构造直角三角形.【针对训练】如图,在△ABC中,AB=AC=2a,∠ABC =15°.求S△ABC.二、课堂小结内容D C A BEF 直角三角形的判定定理 如果一个三角形的两个角 ,那么这个三角形是 三角形. 直角三角形的性质定理 (1)直角三角形的两个锐角 .(2)直角三角形斜边上的中线等于斜边的 . 特殊的直角三角形 在直角三角形中, 所对的直角边等于斜边的一半.1.在Rt △ABC 中,∠C=900,∠A -∠B =300,那么∠A= ,∠B= ;2.如图,在△ABC 中,∠B=50°高AD 、CE 交于H ,则∠AHC=_______.3.在直角三角形中,斜边及其中线之和为6,那么该三角形的斜边长为________.4.如图,在Rt △ABC 中,∠C=90°,∠B=30°,CD 是斜边AB 上的高,AD=3cm ,则AB 的长度是( )A .3cmB .6cmC .9cmD .12cm5.如图,在△ABC 中,AD ⊥BC ,E 、F 分别是AB 、AC 的中点,且DE=DF. 求证:AB=AC6.如图,在△ABC 中,∠C=90°,AD 平分∠CAB 交CB 于点D ,过点D 作DE ⊥AB 于点E ,若∠B=30°,CD=5. (1)求BD 的长;(2)AE 与BE 相等吗?说明理由.等腰三角形第1课时 等腰(边)三角形的认识及性质定理当堂检测j H E DC BA学习目标:1.理解等腰三角形和等边三角形的有关概念.2.借助轴对称图形的性质来理解等腰(边)三角形的性质.3.能运用等腰(边)三角形的性质解决有关问题.学习重点:等腰(边)三角形的性质.学习难点:等腰(边)三角形的性质的运用.自主学习知识链接三角形按边来分类可分为三角形和三角形.证明两个三角形全等的方法有、、、 .新知预习1.如图,把一张长方形的纸片按图中虚线对折,并剪去阴影部分,再把它展开,得到的△ABC 有什么特点?2.有两边相等的三角形叫,相等的两边叫,另一边叫,两腰的夹角叫,腰和底边的夹角叫 (请在下图中标出来)3.等腰三角形是轴对称图形吗?请找出它的对称轴.4.把上面活动中剪出的△ABC 对折,折痕为AD.找出其中重合的线段和角填入下表:重合的线段重合的角D5.你能验证折纸得到的结论吗?试试看.三、自学自测如果等腰三角形的一个内角为50°,那么它的另外两个角为_____________ 在△ABC 中,AB=AC ,∠BAC=90°,AD 是底边BC 上的高,则∠B= °,∠C= °,∠BAD= °,∠CAD= °.四、我的疑惑_____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________要点探究探究点1:等腰三角形的相关概念例1.已知等腰三角形的周长是14cm ,若一边长是6cm ,则另外两边长为 .【归纳总结】遇到等腰三角形的问题时,注意:边有腰与底边之分,角有底角和顶角之分,没有说明的情况下要分类讨论.【针对训练】一个等腰三角形的两边长分别为4,8,则它的周长为( ) A .12B .16C .20D .16或20探究点2:等腰三角形的性质问题:如图,在等腰△ABC 中,AB=AC,点D 是边BC 上一点 已知:AD 平分∠BAC .求证:∠B=∠C ,AD ⊥BC ,BD=DC . 证明:已知:AD⊥BC.求证:AD平分∠BAC,BD=DC.证明:(3)已知:BD=DC.求证:AD平分∠BAC,AD⊥BC.证明:【总结归纳】1.等腰三角形的性质定理(1)等腰三角形的角相等.(简称“”)(2)等腰三角形的平分线、中线、高重合.(简称“”)2.用符号语言表述为:⑴∵AB=AC,∴∠ =∠;⑵∵AB=AC ,AD⊥BC,∴∠ =∠, = ;⑶∵AB=AC ,,∴⊥,∠BAD= ∠CAD⑷∵,AD是顶角的平分线,∴AD⊥BC, =例2.如图,△ABC中,AB=AC,BD、CE分别为∠ABC和∠ACB的平分线.求证:BD=CE.【归纳总结】“等边对等角”常用来证明两角相等.注意:应用的时候,两个角必须在同一个三角形中.【针对训练】如图,已知△ABC为等腰三角形,BD、CE为底角的平分线,且∠DBC=∠F,求证:EC∥DF.CBA例3.如图,在△ABC 中,AB=AC ,AD 是BC 边上的中线,∠ACB 的平分线交AD 于点E ,求证:点E 在∠ABC 的平分线上.【归纳总结】1.“三线合一”是用来证明两角相等、两线段相等及两条直线互相垂直的重要依据. 2.“三线合一”不能逆过来用,即:一个三角形中,已知三线中的“二线”重合(如高和角平分线重合),那么不能直接说明这个三角形是等腰三角形.但可以通过三角形全等来证明这个三角形是等腰三角形. 【针对训练】如图,点D,E 在△ABC 的边BC 上,AD=AE,AB=AC,求证:BD=CE .探究点3:等边三角形的概念及性质问题1.三条边都_________的三角形叫等边三角形.问题2.等边三角形是特殊的等腰三角形,所以它具备 三角形的所有性质. 问题3.如图,在△ABC 中,若AB=BC=CA ,则∠A= ∠B= ∠C= ;理由是:_______________________. 【总结归纳】等边三角形的性质定理:等边三角形的 角相等,并且每个角都等于 .。
冀教版八年级英语上册教案全册
Unit 1 Me and My ClassLesson 1 Li Ming Is Back to SchoolⅠ.Teaching content:1. New words and phrases: grade, student, class, pupil, cousin; be back, have lessons/classes2. Introduce yourself and your schoolⅡ.Teaching goals1. Learn new words: back grade, student, class, pupil & cousin2. Make sure the Ss can introduce themselves and their school3. Talk about the differences between schools in China and other countries.Ⅲ.Key points:1) Some new words and phrases2) Introduce a school by mailⅣ.Difficult points: Compare schools in China and CanadaⅤ.Preparation: some word cards, picturesⅥ.Teaching resources: recorder, pictures or cardsⅦ.Type of the lesson: listening and speakingⅧ.Teaching procedure1: Class opening1)Teacher’s and Ss’ self-introductions.T: I’m your (new) English teacher from today. My name is …. You can call me Mr./Ms.x. I’m glad to learn English with you. I hope to be your friend, so I want to know you now. Please introduce yourself to me. Who wants to be my first friend?S1: My name is Wang Wei.T: Good, thank you Wang Wei. You are a handsome boy. .S2: My name is Li Xiaohua.T: Very good. Glad to get my second friend. Thanks, Xiaohua. Your red skirt is so beautiful. I like red very much. Where are you from?…(The teacher can ask Ss some other questions, such as: How old are you? Do you like English? What’s your favorite color? etc. but do remember to praise each student for whatever he/she says in English.)2)Lead in today’s new lessonT: After you introduced yourselves, I have known some of you. Now I want to know something about our school. Who can tell me? Is it big?S3: Yes, It’s very big.T: oh? How big is it?S4: Every grade has 8 classes.T: Wow, yeah. It’s quite big. Then we have 24 classes (the teacher can pause a little here , waiting for the Ss speak together) altogether. Very good, Who can tell me how many students in our class?S5: Forty-eight.T: Thank you, S5. You know our class well. How many girls in our class?S6: twenty-five.…T: Thank you all for telling me about our school. Who knows schools in some other countries? For example, in Canada, their schools are bigger or smaller? You can guess the answer. Who wants to have a try?S7: bigger?T: Good! A nice try. Thanks.S8: I think, smaller.T: Good, it’s a different answer. Thank you. We’ll get the answer after we learn this lesson. Please turn to Page 2 of your textbook. We have more questions to discuss.2. New lessonStep 1: Ask the Ss to discuss the questions in “Think About It.”Take the first question as an example:T: Have you changed over the summer holiday? S9, what about you?S9: Yes, Mr/Ms.x. I’m taller. I often went swimming with my brother.T: Swimming is good exercise in summer. What about others?S10: I’m thinner bu t taller. I played football everyday with my friends.S11: I’m sorry to say I’m fatter now. I like watching TV at home in the summer holiday.…Step 2: Listening and answering:A) Listen to the tape (of the first e-mail) with some questionsT: We’ve talked about our school and class. Next, let’s listen to Li Ming’s e-mail then you can know schools in Canada are bigger and smaller. Please listen carefully and answer the following three questions:1) Where did Li Ming write the letter/mail?2) How man y pupils are there in Li Ming’s class?(Play the tape )T: Jenny is in Canada. Do you think schools in Canada is bigger or smaller?Ss: (together) smaller.T: Very good. S12, answer question 1, please.S12: (Li Ming wrote the letter) In China.T: Good, S13, How many pupils are there in Li Ming’s class? Do you know “pupils”? Yes, “pupil” means student.S14: There are fifty pupils in his class.T: Right, very good.B) Listen to the tape (of the second e-mail) and answer the following question. (Do the same as in section A)Who will come from the U.K.?Step 3: Reading and discussingA) Fast readingT: Read the two e-mails fast and silently. Then let’s discuss more about them. Here are some more questions:1) Who is the e-mail from and to?2) What can you learn from the two e-mails?3) Do you like schools in Canada?4) Do you going from room to room for your class? Is it good exercise?5) Who is Brian in the second mail? How old is he?…B) Second reading and further discussingT: Read the text a second time. Then we’ll have a further discussion in groups of 4 students. The question for you is: What are the same or different things between the schools in China and Canada. I’ll give you 5 minutes to discuss. Then you should report your discu ss to our class. (Five minutes later, collect the result of their discussion.)T: group 1, what are the same things between the schools in China and Canada?S15(from group 1): There are classrooms in all the schools.T: Good! Anything else? Group 2?S16 (from group 2): There are many teachers.T: Very good! What’s the different things then?S17(from group 3): Schools in China are bigger.S18(from group 4): Every teacher has a different classroom in Canada.S19(from group 5): Students in Canada go from room to room for their lessons. Students in China have class in one room.S20(from group 6): In Canada, there are more teachers in their schools.School begins at 8:30 in Canada, later than in China.…Step 4: Answering questionsEncourage the Ss to ask questions about the text, including the meaning or usage of the new words and phrases in this lesson. Explain to the students and make notes on the blackboard. (see the explanations in the attached reference materials)Step 5: “Let’s Do It” sectionT: It’s our new school term. It’s our first lesson today. Then let’s talk about the new term. Look at the questions in “Let’s Do It!” and talk more.3 question you’ll get: What is the same in the new term? What will be different? What will you do differently?Step 6: Homework1) Write an e-mail to your friend2) Finish off the exercises in the activity book3. Class closingSum up this lesson and end it.T: Today we learned two e-mails. There are some new words and phrases we should remember: grade, student, class, pupil, cousin; be back, have lessons/classes. We also know about the differences between schools in China and Canada. Please practise writing an e-mail to your friends after class and finish your homework. That’s all for today.lesson 2 Many Faces, One PictureⅠ.Teaching content:1. New words and phrases: photo, look like (four skills) ; photograph, wish2. Likes and dislikes3. The Simple Present Tense (positive and negative forms)Structures: I like…/ I don’t like…Ⅱ.Teaching goals1.Master some new words and phrases: photo, look like, take pictures/photos2.Get to know some other words: wish, photograph3.Learn to express likes and dislikes1. Master the negative form of the Simple Present TenseⅢ.Key points:1) look like2) likes and dislikesⅣ.Difficult points: Express one’s dislikes: I don’t like…Ⅴ.Preparation:1) One photo of you2) Some real things such as a banana, a book and some clothes3) Some cards with words of describing yourself4) A big piece of paper and glueⅥ.Teaching resources: recorder, tape , some cards, a big piece of paperⅦ.Type of the lesson: listening and speakingⅧ.Teaching procedure1: Class opening1) Greet the students and check the homeworkT: Hi/Hello/Good morning, everyone/class! How are you today? It’s a beautiful day, isn’t it? Ss: Yes, it’s sunny.T: Ok, Let me check your homework first.(a few minutes later)2) Prepare for the new lessonT: let’s try to remember what we learned yesterday. We talked about Li Ming’s school. In this lesson, we will talk about something new.(Take out the banana, book and a piece of clothes of the bag)T: Can anyone guess why I have brought these things? What is the connection between these things? Please guess. Look, this is my red blouse, I’ve told you I like red very much. And the book, it’s my birthday present last year. Yes, this is a banana. I often buy bananas because I like eating bananas.Ss: You like all of them!T: Very good, you got it!2. New lessonStep 1: lead in(Show the three things )T: These are the things I like best. Next I want to know more about you.Step 2: Discussion before the new lessonT: Look at the questions in “Think About It!” and discuss about them.(introduce the questions to the Ss and give them five minutes to discuss)T: All right! Time for me to know how well you know about your friends. S1, who is your best friend? S1: Wang Gang.T: What do you know about him?S1: He likes basketball very much.T: What about you, S2?S2: My best friend is my cousin, she likes school.T: Good! S3, talk about the favourite photo of yourself, please. When was it taken?S3: Just in the summer holiday.T: Good! What about you, S4? When was your favourite photo taken? And where?S4: It was taken in Beijing last year. My father took the photo for me.Step 3: Discussion about the picture in the textbookT: Look at the picture in your books and let’s talk about it: what is in the girl’s hands? What is she doing?(introduce the word “wish” to the students and make sure they know the meaning of “photo”) Step 4: Further discussionAsk about the title of this lesson: Why is the lesson called “Many faces, One picture?” Step 5: listen and find the answerAsk the Ss to listen to the tape and find the right answer; the answer is in the text. Check the answer with the Ss:Answer: Everyone brings a photo of him or her. We put them together and make a big picture of our class. There are many faces of the students in the big picture.Step 6: Project 1: Make a class pictureMake sure the Ss understand what they must do in the project. Explain what a collage is. (in Chinese if necessary) A collage is a picture made of many little pictures.T: Draw a picture of yourself if you don’t have a photo. Write down at least three senten ces about yourself on a small piece of paper. That’s your name card. Of course, our cards are better. (After a few minutes, Ask several Ss a few questions to help them describe themselves.) The questions can go like this:1. What is your name?2. How old are you?3. How tall are you?4. What are you wearing in your picture or photograph?5. What do you like to do?6. Where do you live?(The class will make a collage.T: First, work in pairs please! Ask your deskmate questions about themselves. Then ask other members in your group similar questions.(Let the Ss find their own partner to practise. Using the sentences in their cards. Encourage the Ss to read what they have written down. Then use their own words.)T: Now, it’s the time f or us to introduce your partners to out class now. S5, introduce your classmates, please.(After the Ss’ introductions, ask them to glue the pictures to a big sheet of paper for the whole class. Several Ss can glue at the same time.)At the end, the class has a collage! Post the collage in the classroom or the halfway for everyone to see.Step 7: Homework1) Read the text in Lesson 2Do the remaining exercises in the activity bookLesson 3 Getting to Know You!Ⅰ.Teaching content:1.New words and phrases: Miss, married/be married, either, glad, really, also, dislike, hate, interest, violin, music, comb2.Likes and dislikes2. I don’t know her.She doesn’t like purple.What does she hate to do?What foods do you love?Ⅱ.Teaching goals1.Learn the usage of the following new words: Miss, married/be married, either, glad, really, also, dislike, hate, interest, violin, music, comb2. Learn how to express likes and dislikes (oneself and others)3. Consolidate the usage of the negative question form of the Simple Present TenseⅢ.Key points:I want to talk to SandraI don’t know her, either.I like donuts bestⅣ.Difficult points: Express one’s dislikes: I don’t like…,either.What do you hate?Ⅴ.Preparation:1) Draw some pictures or find some pictures for the characters in this lesson: Danny, Jenny, Miss Cox and Brain.2) Write down the key new words on cards.1) A rubber toy of dinosaurⅥ.Teaching resources: recorder, tape , word cards, some picturesⅦ.Type of the lesson: listening, speaking and rea dingⅧ.Teaching procedure1. Class opening1) Greet the Ss in everyday English. Help them respond in correct way.2) Correct the exercises of activity books3) Ask “Who’s on duty?” Listen to the students’ report. They may talk about the da te, the weather, their favourite colour, book , sports or film. Give them words and expressions when necessary to help them.4) Draw a picture “an unhappy artist” on the blackboard.T: Look at the “long” face of the artist. He is unhappy, yes? When is he unhappy? Guess the reason, pleaseGive the Ss a few minutes to talk about the reason in order to start the new lesson.2. New lessonStep 1: lead inT: Do you like watching TV? I like some programs very much. For examples, “Talking Straight” (shihua shishuo ) and “Sons and Daughters of the East” (dongfang zhi zi). Do you like them? The project you are going to do is to interview each other. You can ask your classmates many questions just like the hosts or hostess do in the TV programs, such as Wang Xiaoya, Li yong and so on. Of course, you have to use English! But it’s fun! I’m sure you will like it.Step 2: Listen and find use informationT: Listen to the tape please and find the answer of this question: Who does Danny want to interview? (show the r ubber dinosaur and draw some “tears” on its face)T: These are Danny’s tears. Do you like dinosaurs? (Yes!) but Danny is unhappy now. Do you want to know the reason? Read the text on Page 4 with the title of “She’s so Beautiful!”Step 3: Read and discussAfter the Ss read the text fast and silently, let the Ss discuss the following question:Why is Danny scared? ( Because he wants to talk to Sandra)Do you think Danny and Sandra will become good friends? Why? (Yes, they will become good friends. Because girls like dinosaurs and they have a nice talk to each other)What is Sandra like? (She’s beautiful.)Check the answers with the whole class.Step 4: Further reading and further discussionT: Read the text a second time and have a further discussion about it. Answer more questions about it.1) Do they like Miss Cox’s surprise in their English lesson?2) Why can the students call their English teacher “Miss” Cox?3) What colour does Sandra love?4) What does Sandra dislike?5) What are San dra’s interests?Step 5: Explain some new words and phrases (see Text Explanation of Lesson 3)Step 6: Project 21) T: It’s a interview project. So you can be the host or hostess now. You can ask any question that you are interested in. Let’s prepare s ome small cards for the interview first.2) Guide the Ss to make interview cards like this:Interview Chart 1Interview Chart 2Help the Ss remember some useful words for the charts. such as “food” , “clothes”, “animals” and “colours”. List the verbs that students know to fill in the charts.Examples of possible questions and answers:Q: What is your favourite ?A: My favourite is .Q: What do you love/hate to do?A: I love /hate to .Q: Do you like to ?A: Yes, I like to / No, I don’t like to .Q: What do you like best about your school?A: I like best.Q: Who is your best friend?A: is my best friend.(Have Ss find a partner and take turns interviewing each other.)T: Ask your partner those questions and write down their answers. Then fill in your charts. (If time permits, collect the Ss answers and talk about the results of their interviews.)3. Class ClosingT: Practise your likes and dislikes after class, It’s your oral homework and don’t forget the written homework in your activity books. Let’s call it a day. Bye, boys and girls!Lesson 4 On a School DayⅠ.Teaching content:1. New words in this lesson:A:jeans,weekend, wool, cotton, blouse, be made of (four skills) B:round/all year around,iron,tidy (get familiar with them)2. weather and clothesⅡ.Teaching goals1. Master the news in this lesson: jeans,weekend, wool, cotton, blouse, be made of2. Talk about weather and clothes3. Learn the English songⅢ.Key points:He wears pants on a school day/ blue jeans on the weekendSomething different all year aroundⅣ.Difficult points: Wear different clothes in different weathersⅤ.Preparation:1) Prepare some clothes in different seasons: some in winner against cold,some in summer for keeping cool;2) Some color chalks; Some pictures with different clothes3) Draw some sketches of typical clothes in 4 seasons of a yearⅥ.Teaching resources: word cards, some pictures,some clothes,slide projectorⅦ.Type of the lesson: listening, and singingⅧ.Teaching procedure1. Warming up(Singing “Good morning ”song, whose tune is from “Happy birthday ”song. Teacher entered the classroom. )T: Do you like singing? Who can sing a song for us? What about English songs? Introduce some famous but simple songs to the Ss such as “Twinkle stars”, “Jingle bell”, “Mary has a little lamb”, etc. Who can sing a song for us?(Maybe most of the Ss can only sing some Chinese songs. It doesn’t matter, praise the Ss who have sung to get them excited. It’s good for today’s lesson)T: Yeah, you can sin g Chinese songs very well. Today let’s learn an English song, then you can sing to your parents in future. But what kind of songs do you like?2. New lessonStep 1: lead inT: What’s the weather like today? What clothes are you wearing on school days o r on the weekend? There’s a song about it. Would you like to learn the song?(show the Ss the clothes and the word cards to prepare for learning the new words about clothes. Make sure they know the meaning of the song)Step 2: A quick review about clothes wordsReview some old words for clothing, then learn the new words in this lesson: blouse, jeans, be made of, cotton, woolStep 3: Read and understandT: Let’s read the lyrics of the song. Pay attention to the new words we learned just now. Notice the rhym e, rhythm and repetition in the song. (It’s a good preparation for learning the song fast)Step 4: Explanation1) Explain the meaning of the lyrics, especially some sentence structures. Also help Ss to group words in the song. For instance: He wears pants / on a school day, Blue jeans / on the weekend,something different / all year around.1) Ask some questions about the song to make the Ss under it wellWhat does he wear on a school day? (Pants)Does he wear pants every day? (No, he wears blue jeans on the weekend)What is his clothing made in winter? (wool)Does he always wear the same clothes all year around? (No, he wears different )Step 5: listen and learnT: Now let’s listen to tape. You can just listen for the first time to get the tune. Then si ng in a low voice with the tape.Step 6: Practise singingAsk the Ss themselves after having listened to the songs for several times. Then listen to the tape once again. Select one particular student who sings well to be an example or lead to sing for the other students.Step 7: DiscussionDon’t miss the “speech bubbles”! Talk about them with the students. Ask questions like these: Do boys wear dresses? (No, girls wear dresses.)What’s in the girls hands? ( A sweater.)Do you love sweaters?Do you like its colour? What’s your favourite colour?3. Ending class1) Homework: finish the remaining exercises in activity book2) Learn the song after classPrepare another song to share with class next lesson for singing.Lesson 5 The Best ClothesⅠ.Te aching content:1. New words and expressions:A:anymore/not…any more, gray=grey, paint , very much, voice, silly, classmates(four skills) B:backpack(get familiar with them)C: names of persons: Peter, Gina(read)2. Likes and dislikes about clothesⅡ.Teachi ng goals1. Learn to use the new words and phrases: anymore/not…any more, gray=grey, paint , very much, voice, silly, classmates2. Learn to make comments on clothes3. Sentences structures about comments on clothesⅢ.Key points:I don’t like this pair.What did you do to your runners?They look silly.Krista could not think of an answer.Ⅳ.Difficult points:1) The right attitude towards new clothes2) be friendly to classmatesⅤ.Preparation:Prepare a new pair of shoes and old ones and a big paper for a sketch of a dressⅥ.Teaching resources: a big piece of paper, some marks and paints, a pair of old shoes.Ⅶ.Type of the lesson: reading and comprehendingⅧ.Teaching procedure1. Class opening1) Make the class warm by singing the song “On a school Day” together with the students.2) Check up their homework in the activity book. Give them some explanation when necessary 2. New lessonsStep 1: Lead inT: Today let’s continue to talk about clothes. Look at my old shoes. Oh! They are gray, really too old. I like new clothes and shoes. What about you? I also have some nice pictures here for fashionable clothing. (show the pictures to the students.)Step 2: Discussion in “Think About It!”T: We’ve got some questions to discuss in “Think About IT!” Read though all the questions and discuss with your partners. I’ll give you 5 minutes in this section.(Five minutes later, check out Ss’ results of discussion)Step 3: Listen and get key pointsT: Listen to the recorder, please. And answer two questions after that.Q1: Who told Krista to paint her shoes? (Peter)Q2: Who said Krista’s shoes were silly? (Gina)Step 4: Read and understandT: Read the text fast and silently by yourselves then have a discussion about the story. There are more questions for you:1) What do Krista’s runners look like? (They are old and gray.)2) What does Krista do to her runners? (She paints her runners with marks and paints.)3) Is Gina Krista’s good friend? (No, Krista doesn’t like Gina.)4) Why does Gina laugh at Krista? Is it right? (Because Krista paints her shoes and they look silly. No, it’s wrong to laugh at others.)Step 5: Further discussionT: Discuss the story more deeply. Think about the two questions:1) If you were Krista what would you do? (suggested answer1: If I were Krista I wouldn’t paint my shoes. I will just keep them clean and take good care of them. We feel very comfortable when wearing old shoes. Suggested answer 2: I would also paint my shoes. Because I think it’s funny to make old shoes have a different color.)2) If you were Gina what would you say when you see Krista’s painted shoes? (suggested answer 1: If I were Gina I would say :”Hi, Gina, you did a good job. Your runners look so nice now.” suggested answer 2: If I were Gina I would say :”Please buy a pair of new shoes. Old one are still old after painted ”)Step 6: Meaning of the storyT: Read the text once again, please. Try to get the meaning of the story. Then discuss what’s the right attitude towards appearance and classmates.Step 7: “Let’s Do It!” sectionT: Let’s see what we should do in this part.11) Find the reason why Krista wants to cry. Does it recall the similar feeling when you feel embarrassed? Did the feeling last a long time?2) Guess how the story will go without reading the second part in the Reader. Read it for your partner and check whether your guess is right or wrong.3. Class closingT: let’s see our homework for today.1) The third reading in the reader2) Other exercises in the activity book3) The next reading in the students bookSometimes we not only get fun from some stories but also significant experience. “Reading makes a wise person.” So let’s enjoy reading and leaning. Have a nice day. Bye for now.Lesson 6 Meet Ms. LiuⅠ.Teaching content:1.New words and phrases: A: Mr./ Mrs./ Ms. , special, husband, piano, singer, nervous. ( used freely) B: finish, introduce, English (for oral English)1. Introduction of a teacherⅡ.Teaching goals1. Master the new words: Mr./ Mrs./ Ms. , special, husband, piano, singer, nervous.2. Learn how to introduce a teacher.3. Some useful expressions: using Mr./Mrs./Ms. in the correct wayⅢ.Key points:Now he is ready to introduce someone to the classI talked to someone very special.Walking to school in January.Don’t be nervous.Ⅳ.Difficult points: How to present a good introduction of a teacherⅤ.Preparation:1. Write down the key new words on cards.2. Prepare something in our daily life or draw some pictures3. Find some photos of famous hosts or hostesses in magazines, like Wang Xiaoya, Li Yong and so onⅥ.Teaching resources: photo, word cards, some pictures, recorder and slide projectorⅦ.Type of the lesson: speaking and practisingⅧ.Teaching procedure1. Warming up1) GreetingsT: Hi, class! Good morning. How are you doing today? It’s September now, not hot and cold. I like autumn in the four seasons of year. And remember we need to wear different clothes in different seasons.2) A brief review o f yesterday’s lesson3) Duty reportT: Who’s on duty today? Introduce the weather to us today. And describe what clothes your classmates are wearing.2. New lessonStep 1: Lead in(Show the photo of Wang Xiaoya)T: You like her very much, yes? Me, too! Would you like to talk to her? We’ve learned how to interview someone. Imagine you’ve interviewed Wang Xiaoya. And then you are asked to introduce her to your class. Do you know what we want to know about her?Guide the Ss to know the way of introducing someone with some questions:1) Where does she live? (She works in CCTV, so she lives in Beijing.)2) What does she do? (She a good hostess of “Quiz Show” on TV.)3) What is she good at? (She is good at hosting.)4) How is she doing her work? (She works very well. Others even learn from her and her program)5) How do you like her? (She always smiles and I like her very much.)Step 2: key point: introduce how to use Mr./Mrs./Ms correctly(Show a photo of a family)T: Look at this photo, please. It’s a photo of the famous host of Li Yong. Who is the lady besides him? Yes, his wife. And this little girl is their daughter. I can call Li Yong “Mr. Li”. Do you know what we can call his wife? Right! “Mrs. Li”. So what about his daughter?(Let the Ss try to guess. Maybe some of them know the answer. Then guide them to be aware of the differences of the three words.)T: Good, so let’s summarize the usage of the three words: We use “Mr.” before his family name. No matter he is married or not. But we only call a married woman “Mrs.” Right? Then what about a girl, an unmarried one? Yes. Very good. We call a girl “Miss”. We can call a lady “Ms.x” if we don’t know whether she is married or not.Step 3: Discussion of questions in “Think About It!”T: There are some questions for us to discuss on top of Page 8. Read them and think about it. You can discuss with you partners. Then take turns to speak for a introduction.Step 4: Listen and useful informationT: Li Ming will talk on the tape. He also introduced a teacher, Ms. Liu. Listen for the first time and get the answer to this question: How long has Ms. Liu lived in Shijiazhuang? (For two years)Step 5: Further study of the textT: Read the text by yourselves, please, and try to get the information about Ms. Liu as much as possible. Ask me what you can’t understand.Step 6: Discussion and understandingGuide the Ss to discuss the text about Ms. Liu. Check them whether they can understand the text well. The following detailed questions are available:1) How does Ms Liu’s students like her? ( Her students like her very much.)2) How long has she been an English teacher? ( For seven years.)3) Does she always live in China? (No. She once went to school in London to learn English.)4) What food does Ms. Liu like? (Dumplings)5) What’s her favourite animal? (Monkeys)6) Does she have many interests? Give us some examples. (Yes. Ms. Liu has many interests.。
1.11 本册综合 学案(冀教版八年级上册)
Unit 1 Me and My ClassLesson 1 Back to school (New Class)【Learning Aims】I Master the words: physics, recentII Language points:One…and the other…, introduce… to…【Foundation】I Free-talk: How do you like the first day of a new term/school year?Do you have any new subjects? Do you think you will like them?Key Words:__________________________________ ____________________________________________ II New words: Write as the following, then read.eg. rather [ˈrɑ:ðə]adv. 相当;宁可1 physics2 recentIII Translate the following phrases.1 返回到……_________________2 高兴地做某事. __________________3 与……交朋友_________________4 丝绸之路_________________5 与……一样. ____________________6 自我介绍______________________7 想做……. __________________【Direction】I Listen to the passage and tick the correct pictures.II Read the lesson and answer the questions.III Find the following sentences in the text and translate them.1.How was your first day of Grade 8?2.Great! I was happy to see my classmates aftersuch a long holiday.3.I have two new classmates this term. One isSandra and the other is Mary.4.You can introduce yourself to her.5.We have a new subject this term---physics.6.Tomorrow we will make a class picture, but Idon’t have any good recent pictures of myself.7.When you have trouble finding answers toquestions on your own, there are a few things youcan do.8.You can search the web for almost everything.【Self-check】I Multiple choice.1 I have two brothers. One is a teacher and _____is adoctor.A anotherB otherC othersD the other2 ——Mr. Wang, I have trouble _____ the text.——Remember to read it three times at least(至少).A to understandB understandingC understandD understands3 Can you introduce ________ everyone?A your toB you intoC yourself toD your into【Consolidation】I Read again in roles, then get a further understandingof the text.【Expansion】Work in pairs.(p3)_____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________【Assignment】1 Finish off the matched exercise.2 Preview Lesson 2.3 Recite the words and the text.Unit 1 Me and My ClassLesson 2 Many Faces, One Picture (New Class)【Learning Aims】I Master the words: perform, advise, agree, glue;II Language points:Advise…to do…be up to… agree with…【Foundation】I Free-talk: Do you have a favourite photo?Why is ityour favourite? Explain. What is a class picture?Key Words:______________________________________________________________________________II New words: Write as the following, then read.eg. rather [ˈrɑ:ðə]adv. 相当;宁可1 perform2 advise3 agree4 glueIII Translate the following phrases.1 你的一张好看的照片_______2 看起来像___________3 搜寻__________4 建议干……__________5 由……定…_________6同意…__________7 传统的衣服___________8 捡起___________9. 把……粘到……上__________________【Direction】I Listen and circle the correct answers.II Find the following sentences in the text and translatethem.1.You are wearing traditional clothes.2.You played the erhu, and I performed a dance.3.He advised me to choose that one.4.I like the colour in the first picture, but it’s up toyou.5.I agree with you.6.Let’s glue our pictures on the big paper.7.I will put my picture a little bit lower.8.Let’s put it up on the wall.【Self-check】Multiple choice.1 I think physics is very difficult to learn. Do you_______ me?A. agree toB. agree withC. agree onD. agree at2 “Can you _____ your little brother? I’m busy now.”“Sure.”A. inB. put onC. dressD. wear.3 Tom is a little bit ______ than me.A. tallB. tallestC. shortD.taller4 She advised him ________ immediately.A leave B. leaves. C. to leave D. left5.When you leave ___________you.A.put onB. put down.C. put awayD. put up.【Consolidation】Do exercise 3.【Expansion】Work in groups.(p5)【Assignment】1 Finish off the matched exercise.2 Preview Lesson 2.。
1.10 本册综合 学案(冀教版八年级上册)
Unit 8 Celebrating Me!Lesson 47 I Made It! (New Class)【Learning Aims】I Master the words:Peter, loser, fail, Krista, Mexico, miss ,spelled, accepted, awardII Language points:notice sb doing sth, make mistakes, come from, the next day, the end of ,in front of the class, be proud of, because of【Foundation】I Free-talk:Are you good at spelling?What words do you think are hard to spell?What English skills would you like to improve?Key words:__________________________________ ____________________________________________ II New words: Write as the following, then read.eg. rather [ˈrɑ:ðə]adv. 相当;宁可1 Peter,2 loser,3 fail,4 Krista,5 Mexico,6 miss ,7 spelled,8 accepted,9 awardIII Translate the following phrases.1 notice sb doing sth,_____________________2 make mistakes, _______________________3 come from ________4 the next day ____________5 for example ____________________6 the end of ________________7 in front of the class, __________8 be proud of, ________________9 because of__________________【Direction】I Listen to the dialogues and tick the correct answers.Do Exercise1 on page123II Read the lesson and complete the passage with thecorrect forms of the words in the box.Do Exercise2 on the books.【Self-check】根据汉语完成下面的句子。
冀教版八年级上册历史全册教案
冀教版八年级上册历史全册教案本教案是针对冀教版八年级上册历史课程的教学设计。
通过本教案的实施,旨在帮助学生全面了解和掌握八年级上册历史的内容,培养学生的历史思维能力和综合素养。
教学目标:1. 让学生了解中国古代历史中的重要事件和人物;2. 培养学生对历史的兴趣和热爱;3. 提高学生的历史思考能力和分析能力;4. 培养学生的合作研究能力。
教学内容和安排:1. 第一单元:远古史- 研究内容:了解人类的远古生活、石器时代的进化和出现的社会和文化现象,研究中国远古史的基本内容。
- 授课方法:通过展示图片和模型,进行小组讨论,学生演讲,实地考察等方式进行教学。
2. 第二单元:夏商周时期- 研究内容:研究夏商周三代的社会形态、政治制度和经济文化状况,了解这三代的政治、经济和文化发展。
- 授课方法:通过课堂讲解,小组合作阅读,角色扮演等方式进行教学。
3. 第三单元:秦汉时期- 研究内容:研究秦汉两代的政治、军事、经济和文化发展,了解中国古代的统一和繁荣。
- 授课方法:通过讲解,视频观看,小组研究等方式进行教学。
4. 第四单元:魏晋南北朝时期- 研究内容:研究魏晋南北朝时期的政治经济和文化特点,了解这个时期的社会变革和文化繁荣。
- 授课方法:通过讲解,图文解析,小组合作研究等方式进行教学。
教学评价:对学生进行形成性评价和终结性评价的结合,包括平时观察、小组讨论、作业、课堂参与等方面的评估,注重学生的综合素养和合作研究能力的培养。
通过以上教学设计,希望能够提高学生对历史的理解和兴趣,培养他们的历史思维能力和综合素养,促使学生对中国古代历史有更深入的了解,为未来的研究打下坚实的基础。
教案结束。
冀教版八年级生物上册全册教案
八年级上册生物学阜城县码头镇中学王素芬第三单元植物的生活与栽培第一章种子的萌发与播种育苗一、教学目标知识性目标1.举例说出种子的结构2.说出种子的各部分结构在种子萌发中的作用3.描述种子萌发的过程4.分析种子萌发的条件技能性目标1、尝试解剖、观察种子的结构2、运用一定的生物实验器材探究种子的萌发条件情感性目标1、体验自主探究获得知识的乐趣2、认同事物运动的观点二、知识网络结构完整内在条件条件外界条件适量水份非休眠期充足空气寿限之内种子萌发幼苗适宜温度(结构)第一节种子萌发的过程课前准备提前一昼夜浸泡豆种子,若无菜豆,也可以用大豆、豌豆、花生等种子代替。
教学过程身边事本节课有种子长成幼苗的现象入手,引出本节课要学习、研究的主题。
教师可以根据司机情况,利用身边事例进行形象的引入,例如可以列举春播、秋播等农村学生比较常见的,而且都比较熟悉的生产实际,也可以从学生种植花草种子的亲身经历引出。
探究竟“探究竟”针对本节课的主题安排了两个活动,分别学习和认识种子的结构和萌发过程。
大家谈两个问题分别是针对两个学习活动提出来的,建议分别与活动的总结和整合结合起来。
知识链“知识链”的内容是对“探究竟”的总结和扩展,一共分为三个自然段,即三部分。
第一部分是对第一个探究活动的总结,第二部分是对第二个探究竟活动的总结,解答时要分别结合“大家谈”的问题。
第三部分有关种子休眠问题。
实际用“实际用”是联系本节课知识内容,针对播种中的实际问题提出的。
课堂上处理这个问题时,最好也引导学生自己得出。
第二节种子萌发的条件教学过程身边事本节课“身边事”关键都是要从学生身边熟悉的事件出发,引导学生对种子萌发的好奇心。
探究竟这是一节典型的探究课,需要学生提出假设并完成实验。
学生提出种子萌发的条件可能有很多,教师要引导同学们根据已有的知识分析排除一些,对于一些不以确定是否为种子萌发必要条件的,可以由每组选择设计并完成实验验证。
大家谈典型探究课的最后总结整合尤其重要,处理得当,不但能培养学生合作学习的能力,而且还可以使学生提高表达能力,并能激发创新的火花。
冀教版初中数学八年级上册全册学案(DOC)
第十六章勾股定理第一节勾股定理学习目标1.掌握勾股定理.2.学会利用勾股定理进行计算、证明.3.了解有关勾股定理的历史.4.在定理的证明中培养学生的拼图能力.课前预习方案自主学习相传2500年前,毕达哥拉斯在朋友家做客时,发现朋友家用砖铺成的地面中反映了直角三角形三边的某种数量关系.我们只看到了地砖的装饰效果,数学家却看到了这样一个图1,他发现了这样一个图形,并从这一图形发现了等腰直角三角形三边的关系.你能根据图2观察分析三个正方形的面积S A、S B、S C有什么关系?中间的等腰直角三角形三边有什么关系?你能用毕达哥拉斯的方法探究一般直角三角形的三边是否也有这样关系吗?知识链接正方形的面积.课堂学习方案知识结构1.勾股定理:直角三角形两直角边a、b 的平方和等于斜边c 的平方.a2+b2=c22.勾:最短的直角边.股:较长的直角边.弦:斜边.典型例题例.如图,将矩形ABCD(AB<AD)沿BD折叠后,点C落在点E处,且BE交AD于F,若AB=4,BC=8,求DF的长.(03年泰州)分析:折叠问题是学生感兴趣的问题,如何用数学知识解决折叠中的计算问题,也是我们必须思考的问题.由折叠知:△BDE≌△BDC故∠1=∠2又ABCD是矩形所以AD∥BC所以∠1=∠3即∠2=∠3故FD=FB设FD=FB=x,则AF=8-x在Rt△ABF中,()=+-222x48x解得=x5即DF的长为5.限时课堂训练基本练习1.在Rt△ABC中,∠C=90°⑴已知:a=6,b=8,则c= .⑵已知:a=40,c=41则b= .ACB 图1 图2 A DC BFE123⑶已知:c=13,b=5,则a= .2.如图,直线上有三个正方形a 、b 、c,若a 、c 的面积分别为5和11,则b 的面积为( ) A.4 B.6 C.16 D.553.有两棵树,一棵高6米,另一棵高3米,两树相距4米,一只小鸟从一棵树的树梢飞到另一棵树的树梢,至少飞了 米. 4.人民海关缉私巡逻艇在东海海域执行巡逻任务时,发现在其所处位置O 点的正北方向10海里处的A 点有一涉嫌走私船只,正以24海里/小时的速度向正东方向航行,为迅速实施检查,巡逻艇调整好航向,以26海里/小时的速度追赶,在涉嫌船只不改变航向和航速的前提下,问需要几小时才能追上?(2003年青岛)拓展思维 如图,A 、B 两个小集镇在河流CD 的同侧,分别到河的距离为AC=10千米,BD=30千米,且CD=30千米,现在要在河边建一自来水厂,向A 、B 两镇供水,铺设水管的费用为每千米3万,请你在河流CD 上选择水厂的位置M,使铺设水管的费用最节省,并求出总费用是多少?第二节 由边的数量关系识别直角三角形 学习目标1.掌握直角三角形的判别条件.2.熟记一些勾股数.课前预习方案自主学习问题:据说古埃及人用下图的方法画直角:把一根长蝇打上等距离的13个结,然后以3个结,4个结、5个结的长度为边长,用木桩钉成一个三角形,其中一个角便是直角.这个问题意味着,如果围成的三角形的三边分别为3、4、5,有下面的关系“32+42=52”,那么围成的三角形是直角三角形.画画看:如果三角形的三边分别为2.5cm,6cm,6.5cm,有下面的关系,“2.52+62=6.52,画出的三角形是直角三角形吗?换成a bc A BCDL三边分别为4cm 、7.5cm 、8.5cm.再试一试. 按照特殊到一般思路,你能归纳猜想出“如果三角形三边a,b,c 满足a 2+b 2=c 2,那么这个三角形就为直角三角形的结论吗?知识链接直角三角形有如下性质:⑴有一个角是直角⑵两个锐角互余⑶两直角边的平方和等于斜边的平方⑷在含30°角的直角三角形中,30°的角所对的直角边是斜边的一半.课堂学习方案知识结构如果三角形的三边长a,b,c 满足a 2+b 2=c 2那么这个三角形是直角三角形. 典型例题,∠B=90°,AB=3,BC=4, CD=12,AD=13,求四边形ABCD 的面积. 解:连结AC∵∠B=90°,AB=3,BC=4∴AC 2=AB 2+BC 2=25(勾股定理) ∴AC=5∵AC 2+CD 2=169,AD 2=169 ∴AC 2+CD 2=AD 2∴∠ACD=90°(勾股定理逆定理) S 四边形ABCD =S △ABC +S △ACD =21AB·BC+21AC·CD=36 限时课堂训练基本练习 1.以下列各组数为边长,能组成直角三角形的是( )A. 8,15,17B. 4,5,6C. 5,8,10D. 8,39,40 2.△ABC 中,如果-+=2(a b)(a b)c ,则△ABC 是 三角形,且∠ =90°. 3.如图,ABCD 是正方形,AE=12AB,BF=14BC, 求证:DE ⊥EF拓展思维如图,三角形三边上的半圆面积从小到大依次记为S 1,S 2,S 3,且S 1+S 2=S 3,试判定这个三角形是什么三角形.第三节 勾股定理的应用学习目标1.能运用勾股定理及直角三角形的判别条件(即勾股定理的逆定理)解决简单的实际问题.2.培养从“形”到“数”和从“数”到“形”课前预习方案自主学习ABC D3题图一道有趣的问题,这个问题的意思是:有一个水池,水面是一个边长为10尺的正方形.在水池正中央有一根新生的芦苇,它高出水面1尺.如果把这根芦苇垂直拉向岸边,它的顶端恰好到达岸边的水面.请问这个水池的深度和这根芦苇的长度各为多少?线段中垂线定理;利用轴对称确定最短距离1.△ABC为Rt△且∠C=90°⇔=+222c a b2.利用勾股定理的逆定理,可以判定一个角为直角,从而判定直角三角形,也可以用.AD,点D落在BC边的点F处,BC=10cm,AB=8cm,求:⑴FC的长.⑵EF的长.解:(1)在Rt△ABC中由勾股定理得AF2=AB2+BF2∴ 102=82+BF2∴BF=6FC=BC-BF=4(cm)(2)在Rt△ABC中由勾股定理得EF2=FC2+(8-EF)2∴EF2=42+(8-EF)21.在水塔O的东北方向32m处有一抽水站A,东南方向24m处有一建筑工地B,在AB间建一条直水管,则水管的长为( )A.45cmB.40cmC.50cmD.56cm2.两只小鼹鼠在地下打洞,一只朝前方挖,每分钟挖8cm,另一只朝左挖,每分钟挖6cm,10分钟之后两只小鼹鼠相距( )A.50cmB.100cmC.140cmD.80cm3.如图,下列三角形中是直角三角形的是( )4.如图,小李准备建一个蔬菜大棚,棚宽4m,高3m,长20m,棚的斜面用塑料薄膜遮盖,不计墙的厚度,请计算阳光透过的最大面积为 .5.为了丰富少年儿童的业余生活,某社区要在如图所示AB所在的直线建一图书室,本社区有两所学校所在的位置在点C和点D处,CA⊥AB于A,DB⊥AB于B,已知AB=25km,CA=15km,DB=10km,试问:图书室E应该建在距点A多少km处,才能使它到两所学校的距离相等?如图,A城气象台测得台风中心在A城正西方向320km的B处,以每小时40km的速度向北偏东60°的BF方向移动,距离台风中心200km的范围内是受台风影响的区域.⑴A城是否受到这次台风的影响?为什么?⑵若A城受到这次台风影响,那么A城遭受这次台风影响有多长时间?5题图EDCBAD51213C567B758A6353题图4题图第十七章 实数 第一节 平方根 第一课时 平方根的认识学习目标1.了解数的平方根的概念,会用根号表示一个数的平方根.2.了解开平方与平方是互逆的运算,会利用这个互逆运算关系求某些非负数的平方根.3.通过学习算术平方根,建立初步的数感和符号感,发展抽象思维.课前预习方案自主学习1.25的平方根的是_________;49的平方根是________;0的平方根是________.2.11_____2______44=±=;. 课堂学习方案知识结构 1.平方根:(1)平方根的定义:一般地,如果一个数x的平方等于a ,即x 2=a ,那么这个数x 就叫做a 的平方根,也叫做a 的二次方根. (2)平方根的表示方法:一个正数a 的正的平方根,记做a ,读作“根号a ”,其中a 叫做被开方数,正数a 的负的平方根,记做a ,读作“负根号a ”.这两个平方根可记为a .(3) 平方根的性质:一个正数有两个平方根,它们互为相反数;0只有一个平方根,它是0本身;负数没有平方根. 2.开平方运算:(1)开平方的定义:求一个数的平方根的运算.(2)与平方运算的关系:互为逆运算.可以用平方运算来检验开平方的结果是否正典型例题 例1.求下列各数的平方根: (1)144 (2)1625 (3)0 (4)719点拨:求一个数的平方根,可通过平方运算来解答,如果求一个带分数的平方根,要先化为假分数,再求其平方根.解:(1)∵(±12)2=144, ∴144的平方根是±12;(2)∵2416525⎛⎫±= ⎪⎝⎭,∴1625的平方根是45±;(3)∵02=0,∴0的平方根是0;(4)∵719=169,241639⎛⎫±= ⎪⎝⎭,∴719的平方根是43±.ABE F 东 北例 2.如果一个正数的平方根是2x-3和5-3x ,求这个正数. 点拨:解决此类问题的关键是利用一个正数有两个平方根,它们互为相反数这个特性. 解:由正数的平方根性质可知, 2x-3和5-3x 互为相反数,即(2x-3)+(5-3x)=0,2-x=0,x=2, 所以这个正数是1.1.下列说法正确的有 ( ) ①1的平方根是1②9是(-9)2的平方根 ③-9的平方根是±3 ④0没有平方根A.0个B.1个C.2个D.3个 2.下列各式计算正确的是 ( )A.3=±B.3=2=± D.3=±3.如果x 2=25,那么6-x 的值是 ( ) A.±1 B.±5 C.1或11 D.1或4 4.填空:.(1)81的平方根是 ,(2)0.16的正的平方根是 , (3)(-3)2的平方根是 , (4)2-2的负的平方根是, (5)______=,(6)______=.5.已知一个正数的一个平方根是0.3,则这个正数的另一个平方根是________. 6.若4a+1的一个平方根是0.5,则 a_______.________.8.若3x-5有两个平方根,则x 的取值范围 是______________.9.若一个正数的平方根是3x-5和2x-10,则这个正数是___________.a 和b 之间,此时a,b 的值分别是____________.11.学校要种一块面积为28.26㎡的圆形花坛,它的半径应为多少米?(π取3.14)12.小明卧室的面积为16平方米,计划用100块相同的正方形地板砖铺地面,那么所需要正方形地板砖的边长应是多少? 观察下列各等式,再回答下列问题:111111112=+-=+;111112216=+-=+;1111133112=+-=+;… (1) 请你根据上面三个等式提供的信息猜想(2)请你按上面的各式反映的规律写出含n 的式子表示的等式(n 为正整数).第二课时 算术平方根的认识学习目标1.理解算术平方根的概念、表示法以及a ≥0(a ≥0)的性质.2.明确平方根、算术平方根的区别、联系.3.会求一个非负数的算术平方根.课前预习方案自主学习1.81的平方根是_____,算术平方根是_____.11______2______4=-=,, ()21.21_______5____=-=,.知识链接1.平方根的特征.2.平方根的表示方法.课堂学习方案知识结构1.算术平方根的概念及表示法:概念:一个正数的正的平方根,叫做这个数的算术平方根.规定:0的算术平方根是0.表示法:正数a a ,读作“根号a ”. 强调:书写时根号一定要把被开方数盖住. 2.算术平方根的性质:算术平方根具有双重非负性:①被开方数a 是非负数,即a ≥0; a 本身是非负数,即a ≥0.也就是说,正数的算术平方根是一个正数,0的算术平方根是0,负数没有算术平方根.3.平方根、算术平方根的区别、联系: 区别:①定义不同 ②表示方法不同; ③个数不同 ④取值范围不同; 联系:①平方根包含着算术平方根; ②取值条件相同:条件为非负数. 典型例题例1.求下列各数的算术平方根2.25; 121; (-3)2点拨:依据算术平方根的定义对其求值,如果被开放数为小数、分数则一般先化为假分数,须注意符号.解:⑴∵2.25=94,23924⎛⎫= ⎪⎝⎭,∴2.25的算术平方根是32,32.252=; ⑵∵112=121,∴121的算术平方根是11, 12111=;⑶∵(-3)2=32,∴(-3)2的算术平方根是3, ()233-=.例2.已知a 、b为有理数,a 52102ab 4--=+求a 、b 的值.点拨:利用算术平方根所具有的非负性,即被开方数是非负数,组成不等式组即可. 解:根据算术平方根的性质,得:a 50102a 0-⎧⎨-⎩≥,≥,所以a 5a 5⎧⎨⎩≥,≤,即a=5. 当a=5a 52102a b 4--=+变b 4=+, 即b+4=0,解得b=-4. ∴a=5,b=-4.1.下列说法正确的是 ( ) A.4是2的平方根B.2是4的算术平方根C.0的算术平方根不存在D.-1是-1的算术平方根( )A .4 B.±4 C.2 D.±2 3.(2009,武汉( )A.-3B.±3C.9D.34.(2009,天津) 若x,y 为有理数,且满足x 20+=,则2009x y ⎛⎫ ⎪⎝⎭的值为( ) A.1 B.-1 C.2 D.-25.若2a =25,b =3,则a+b 为 ( )A.-8B.±8C.±2D.±8或±2 6.若一个数的算术平方根为3,那么这个数 的平方根是______,这个数的平方是 ______. 7.________,平方根是________.8. ____的算术平方根等于它本身, ___的平方根等于它本身. 9.y 3=成立,则代数式y x =________.10.(2008,长沙)已知a,b 为两个连续整数,且a b,则a+b=________.12.求下列各式中的x 的值:⑴2x 2=288 ⑵(3x-2)2-1=8⑶213x 22703⎛⎫+-= ⎪⎝⎭13.在直角三角形中,a,b 是两条直角边,c 是斜边.(1)已知a=3,b=4,求c 边. (2)已知b=35,c=1,求a 边.已知x+2y+3z=18,4x+3y+2z=27,试求x+y+z 的平方根和算术平方根.11.当一个数n 为_______时,2n 1-有两平 方根,平方根是______.(在横线上填一 个你认为合适的值)第二节立方根学习目标1.了解立方根的概念,会用根号表示一个数的立方根,了解开立方与立方互为逆运算,能用立方运算求一些数的立方根.2.能用立方根解决一些简单的实际问题.3.在一定的情境下,理解立方根的概念,使学生不断获得解决问题的经验,提高思维水平,学习中要注意感悟“类比”在知识产生和发展过程中的作用.课前预习方案自主学习1.125的立方根是______;-64的立方根是 _______.()33327______2_______=-=;.知识链接1.平方根、算术平方根的定义.2.开平方运算..课堂学习方案知识结构1.立方根:(1)立方根的定义:一般地,如果一个数x 的立方等于a,即3x a=,那么这个数x就叫做a的立方根,也叫做a的三次方根;(2)立方根的表示方法:任何一个数都有立3a,读作“三次根号a”,其中a叫做被开方数,3叫做根指数,的左上角,不能省略不写;(3)立方根的性质:一个正数有一个正的立方根;;一个负数有一个负的立方根;0的立方根是0.2.开立方运算:(1)开立方的定义:求一个数的立方根的运算;(2)与立方运算的关系:互为逆运算.可以用立方运算来检验开立方的结果是否正确.3.两个公式:⑴33a a=,33a a-=-典型例题例1.求下列各数的立方根:⑴-8;⑵0.027;⑶27125-.思路分析:依据立方根的定义求立方根. 解:⑴∵()328-=-,∴-8的立方根是-2,382-=-;⑵∵30.30.027=,∴0.027的立方根是0.3,30.0270.3=;⑶∵33275125⎛⎫-=-⎪⎝⎭∴27125-的立方根是35-,即35=-. 例2.已知x-2的平方根是±2,2x+y+7的立方根是3,求x 2+y 2的平方根. 点拨:解决此题的方法是依据开立方与立方是互为逆运算的,开平方与平方是互为逆运算的.解:因为x-2的平方根是±2,所以x-2=4 解得x=6.因为2x+y+7的立方根是3,所以2x+y+7=27又因为x=6,所以y=8.所以x 2+y 2=62+82=100所以x 2+y 2的平方根是10=±.1.下列说法正确的是 ( )A.任意数a 的平方根有2个,它们互为相反数B.任意数a 的立方根有1个 C.-3是27的负的立方根D.(-1)2的立方根是-1 2.下列判断正确的是 ( )A.64的立方根是±4 B.(-1)1-的立方根是1C的立方根是2 D.=a ,则a =0的立方根是 ( )A.±4 B.±2 C.24.一个数的算术平方根与它的立方根的值 相同,则这个数是 ( ) A .1 B .0或1 C .0 D .非负数5.4a =-成立,则a 的取值 范围是 ( ) A.a ≤3 B.-a ≤4C.a ≥4D.一切实数6.如果a <0,那么a 的立方根是 ( )C.D.7.若2x 64==_____.8.立方根是-8的数是_______, 的立方根是________.9.若3x 125=,则x =_______;33x 6=, 则x =________,若33x (4)=-,则x =____.10.当x <7=_________.11.-27 __________. 12.求下列各式的x :⑴332x 64-= ⑵3(x 3)270++=已知A =m 是n -m +3的算术平方根,B =m 2n -是m +2n 的立方根,求B -A 的立方根.第三节 实数 第一课时 实数的分类学习目标1.知道什么是无理数.2.了解实数的意义,了解实数的分类.3.理解实数的相反数、倒数和绝对值的意义.4.会有理数估计一个无理数的范围.课前预习方案自主学习 1.在2,2,π,5中是无理数的有________.2.3-的相反数是_____,35的绝对值是_______,17-的倒数是_______. 知识链接1.正方形的面积公式:2s R =π. 2.有理数的概念、分类.3.在有理数范围内的相反数、倒数、绝对值 课堂学习方案知识结构1.无理数的概念:无限不循环的小数;2.常见的无理数:⑴圆周率π及含π的数 23 ⑶看似循环但不循环的小数,如: 0.121221222122221…;⑷易出错的分数,如:117; 3.实数的概念:有理数与无理数统称为实数;4.实数的分类:⑴按实数的定义分类: ⑵按实数的性质分类: 5.实数a 的相反数是-a ; 实数a(a ≠0)的倒数是1a; 实数a 的绝对值:a(a 0)a 0(a 0)a(a 0)>⎧⎪==⎨⎪-<⎩6.有理数估计一个无理数的范围的方法:估 算法典型例题例1.把下列各数填入相应的集合内:-5,3.7.3332,8,25,3,0.3,,43π-- 0.2121121112...(21每两个之间多一个)填入相应的集合里.有理数集合_______________,无理数集合_____________________,正实数集合_______________,负实数集合_____________________.点拨:利用无理数的定义及常见的几种无理数进行判断.解:有理数:3825,23-,0.3-π,0.2121121112...(21每两个之间多一个)正实数:0.30.2121121112...(21每两个之间多一个)负实数:-5,23-,-π. 例2.的整数部分是m,小数部分为n,求n 2-2m 的值. 点拨:解决此类问题的关键是确定m 与n 的值,的整数部分m 的值,再由,求出n 的值. 解:因为4<6<9<<,即2<3的整数部分为2, 即m=2,而小数部分为n,则-2.所以n 2-2)2-2×2)2-+4-4=6-.1.下列实数2π,227,0.1414中,无理数的个数是 ( )A .2个B .3个C .4个D .5个 2.下列语句中正确的是 ( ) A .带根号的数是无理数B .不带根号的数一定是有理数C .无理数一定是无限不循环的小数D .无限小数都是无理数3.下列各组数中互为相反数的是 ( )A.5B.5-和15C.5-D.5--和()5-- 4. (2005,陕西)点A 为数轴上表示-1的点,将A 在数轴平移3个单位到点B ,则点B 表示的实数为 ( ) A .3 B .2C .-4D .2或-4 5.面积为13的正方形的边长为_________. 6.写出和为5的两个无理数 ____.7.a a=____a .8.观察下列各式:311+=231,412+=341,513+=451,……,请你将猜想到的规律用含自然数n (n ≥1)的代数式表示出来是 . 9.已知mn数部分,求m -n 的值. 如图,正方形网格中的每个小正方形边长都是1,任意连结这些小正方形的顶点,可得到一些线段.请在图中画出1352===AD AC AB 、、这样的线段.第二课时实数与数轴的关系学习目标1.2.了解有理数运算律在实数范围内仍然适用.课前预习方案自主学习比较大小:(1)3 10;(2)π 3.142;(3)8-7.知识链接1.有理数与数轴上点的关系:有理数可以用数轴上的点来表示.2.两个比较大小常用的方法:作差法、作商课堂学习方案知识结构1.实数与数轴上的点是一一对应的.2.实数范围内的大小比较:常用的方法:①作差法:如果a-b>0,则a>b,如果a-b<0,则a<b;②数轴法:正数大于负数,两个负数,绝对值小的反而大,数轴上右边的点表示的数总比左边的点表示的数大;.典型例题例1.比较下列各组数的大小:⑴524;⑵10--π和;⑶()11m n0m n>>和.思路分析:实数大小的比较,可根据不同的题目选择不同的方法,选择的依据是选择合理,快捷的方法.解:⑴因为52=25,22424=,而25>24,所以524>⑵因为21010=,()22 3.1415π=,而2210 3.15>>π,10>π,所以10-π.⑶因为1nm1mn=,而m n0>>,所以n01m<<,所以11m n<.例2.实数a、b在数轴上的位置如图所示,则化简2a b a-)A.2a+b B.b C.2a-b D.ba点拨:由于实数与数轴上的点是一一对应的,因而利用数轴可以清晰地反映出两个实数的大小情况,为解决问题提供形象直观的 方法.解:由图可知:a <0<b,所以()a b a b -=--a a ==-,()()a b a b a b -=----=,故正确答案是B.1.下列说法错误的: ( ) A.每一个整数都对应着数轴上的一个点 B.每一个无理数都对应着数轴上的一个点C.有理数与数轴上的点是一一对应D.数轴上的每一个点都对应着一个实数2. (2009,宁波)下列四个数中,比0小的数是( )A .23B C .π D .1- 3.(2009,台州)如图所示,数轴上表示2的对应点分别为C 、B ,点C 是AB 的中点,则点A 表示的数是( ) A . B .2 C .4D 2(第3题) 4. (2009,江苏省)如图,数轴上A B 、两点分别对应实数a b 、,则下列结论正确的是 ( ) A .0a b +> B .0ab > C .0a b ->D .||||0a b ->5.设02a =,2(3)b =-,c =,11(2d -=,则a b c d ,,,按由小到大的顺序排列正确的是 ( ) A .c a d b <<<B .b d a c <<<C .a c d b <<<D .b c a d <<<6.已知0<x <1,那么在x ,x1,x ,x 2中最大的是 ( ) A .x B .x 1C .xD .x 27.____. 8.若0≤x ≤1,____=.9.与3是接近的整数是________.10.实数a 在数轴上的位置如图1所示,则|1|a -= .11.如果a =5,b =3,比较大小:b a _______a b已知实数a 满足 a =,求()2a 2005-的 值.(第4题) 10题图第四节 用计算器开平(立)方学习目标1.会用计算器求一个数的平方根和立方根.2.体会和感受用计算器开方运算的优越性和使用计算器的程序化思想.课前预习方案自主学习113;393;352π.知识链接1.用计算器进行有理数运算的方法.2.平方根的意义.3.立方根的意义.课堂学习方案知识结构1.会用计算器求一个数的平方根.2.会用计算器求一个数的立方根.3.用计算器进行开方运算时,一般是按从左到右依次输入,但遇到被开方数是分数时,要将其加上括号;遇到被开方数是负数时,要将“-”加上括号. 典型例题 例:(1)任意找一个你认为很大的正数, 利用计算器对它进行开平方运算, 对所得的结果再进行开平方运算…… 随着开方次数的增加,你发现了什么? (2)改用另一个小于1的正数试一试, 看看是否仍有类似的规律.思路分析:通过计算器的操作,提高了同学们的动手操作能力,同时也培养了同学们分析问题的能力.解:无论被开方数是大于1还是小于1的正数,按要求用计算器算出的最终结果都是1.限时课堂训练基本练习1.利用计算器求下列各式的值: (结果保留4个有效数字) (1 3.142 (2)110-(3382 (430.2574-2.任意给定一个负数,利用计算器不断进行 开立方运算,随着开立方次数增加,结果 越来越趋向 ( ) A.0 B.1 C.-1 D.无法确定3.如图,若数轴上的点A 、B 、C 、D ,分别表 示数-1,0,2,3,则表示27- 在线段 ( )12345-1-2AA .AB 之间 B. BC 之间 D. BD 之间 拓展思维 已知按一定规律排列的一组数:12, 3题图31920,,,.请你从中选取若干个数设计一种方案,使它们的和大于3.第五节实数的运算第一课时二次根式学习目标1.使学生了解有理数的运算律在实数范围内仍然适用.2.掌握二次根式和最简二次根式的概念.3.会熟练的进行二次根式的化简及乘法和除法的一般运算.课前预习方案自主学习1.计算:23_____,21_____2=.2.130.57________.925_____⨯=455____=.知识链接1.有理数的运算法则和运算律;①加法交换律;②加法结合律;③乘法交换律;④乘法分配律.2.平方根的定义.3.立方根的定义.课堂学习方案知识结构1.二次根式的定义:一般地,把形如)a a0≥的式子叫做二次根式.须注意的要点:①“a≥0”是定义中的一个重要组成部分,不可省略;②a可以为数也可为代数式;③二次根式有意义的条件是:a≥0.2.二次根式的基本性质:()a0a0≥;②()2a a a0=≥;③aa=24.最简二次根式的概念:(1)被开方数中的因数是整数,因式是整式;(2)被开方数中不含能开得尽方的因式或因数;我们把符合这两个条件的二次根式,叫做最简二次根式.5.二次根式的化简的基本步骤:一观察,二变形,三开方.6.两个重要性质公式:积的算术平方根与商的算术平方根:)a b a b a0b0∙=≥,≥;)a aa0b0b b=>≥,.典型例题例1.把下列各式化成最简二次根式:12112;(3) 245a b思路分析:化简时,往往需要把被开方数分解因式或分解因数,把被开方数中能开得尽方的因数或因式用它的算术平方根代替后移到根号外.解(2)=2;(3)例2.已知a+b=-3,a ∙b=2的值.22+=32. 我们知道,当a ≥00≥0,0,其和必然不小于零,•而题中结果却是负数,说明计算过程有错误,请你指出错在哪一步,错的原因是什么,正确解法又该怎样?点拨:解决这类题应注意挖掘题目中的隐含条件,题目中错解的原因就在于没有根据实数的运算法则分析清楚字母a ,b 的取值均为负,而造成了解题失误,•如果题目中确实无法搞清字母的符号,那么就应该分类讨论,不能想当然.正确的解法是:因为a+b=-3,ab=2,所以a<0,b<0,=-a-b=-a b+32.1.x 的取值范围( ) A .x ≥3 B.x>3 C.x<3 D.x ≤32.下列根式中,最简二次根式的是( ) A.3.0 B.52C.c ab 22D.92+a 3.化简32的结果是 ( ) A.25 B.24 C.23D.26 4.长方形长为cm 6,则面 积为 cm 2.5.计算22)3()3(--=___________. 6.计算27×32÷6=_________. 7.已知一个自然数的算术平方根为a ,则比 这个自然数小5的数是_________. 8.已知直角三角形两直角边x,y 的长满足 2x 40-=,则第三边的 长度为____________. 9.化简a1a -得_____________.用长为3cm ,宽为2.5cm 的矩形纸牌30张摆成一个正方形,你怎样摆,•试着摆一下.拓展:请同学们把纸牌的数量改变,如120张,又该怎样摆呢?第二课时同类二次根式学习目标1.掌握同类二次根式的概念.2.会熟练的进行二次根式的加减运算及混合运算.3.体会类比的数学思想在数学中的应用.课前预习方案自主学习1.28______=.2.130.527________.3.51530_______=.知识链接1.实数的运算法则、运算律和乘法公式:①加法交换律;②加法结合律;③乘法交换律;④乘法分配律.乘法公式:平方差公式,完全平方公式.2.最简二次根式的化简.课堂学习方案知识结构1.同类二次根式的概念:几个二次根式化为最简二次根式后,如果被开方数相同,那么这几个二次根式叫做同类二次根式.2.判断是同类二次根式的方法:定义法.3.二次根式的加减运算:一般步骤:⑴将每个二次根式化简⑵找出同类二次根式⑶合并同类二次根式.4.二次根式的混合运算:⑴运算顺序:同实数先乘方、开方,再乘除,最后加减,有括号的先算括号里面的;⑵运算律、运算法则、乘法公式同样适用.典型例题例1.判断下列各式哪些是同类二次根式:112120.53227,,,,思路分析:将每个根式应先化为最简二次根式,再依据定义进行判断.12223⨯3;1328324===;120.522===1133327273819⨯===⨯,120.532,,是同类二次根式11227,是同类二次根式.例2.计算:⑴)2313-(2)(523523点拨:解决此类题能用公式时就利用公式,可使运算简便.解:⑴)21-=22211++-=31+- =4.⑵22=(222⎤⎡-⎥⎣⎦=()258-=9例3.①验证:==②验证:== (1)按照上述两个等式及其验证过程的基本思路,猜想(2)针对上述各式反映的规律,写出用n (n 为自然数,且n ≥2)表示的等式,并给出证明. 点拨:解决阅读题的关键是看懂题目所给的阅读材料,此题属类比型总计题,用题目中所给的信息验证所给的问题,要通过题目中每一步变形的情况,类比出自己进行验证时所采取的措施.联系本题,第一步,先把根号外的因式平方后移到根号内;第二步,在被开方数的分子上配上一个常数,进行分解变形;第三步,整理结果. 解:(1)(2)反映的规律:证明:=1.计算下列各式:⑵⑶在一节数学探究课上,张老师出示了下列命题:已知正数a 和b,①若a+b=2,≤1;②若a+b=3,则有ab≤32;③若a+b=6,则有ab≤3.读完上述三个命题后,老师告诉同学们上述命题均为真命题.试猜想,若a+b=7,则ab≤________.若a+b=n,则ab≤_______.我们可以得到一个规律:__________.试对上述规律进行证明.第三课时实数的运算学习目标1.会用计算器进行简单的实数的混合运算并按要求取近似值.2.进一步体会计算器的使用在计算中的优越性.课前预习方案自主学习用计算器求下列各值(结果精确到0.01) 251______=;623______=.知识链接1.二次根式的混合运算.2.计算器的开平方和开立方运算.3.近似数的精确度的表示.课堂学习方案知识结构1.计算器进行混合运算时按键顺序,注意:第二功能键的使用.2.近似数的精确度的常用表示:⑴有效数字⑵精确到十分位(百分位等) ⑶精确到0.1(0.01等).典型例题例.某开发区是长为宽的3倍的一个长方形,它的面积为120000000㎡.⑴开发区的宽有10000m吗?⑵如果要求误差小于100m,它的宽大约是多少?⑶开发区内有一块正方形的地将用来建管理中心,它的规划面积是8500㎡,你能计算一下它的边长吗?(精确到1m)思路分析:在日常生活中,我们常用到二次根式运算,而计算器的使用会给我们带来极大的方便.解:⑴设开发区的宽为xm,则长为3xm,由题意得:3x2=120000000,所以:x2=40000000,x=100040.4010<,所以开发区的宽没有10000m;40 6.3≈,所以开发区的宽约为6300m;⑶设正方形的边长为ym,由题意得,2y8500,y85001085===859.22≈,所以y92≈,即管理中心的边长为92m.限时课堂训练基本练习1.一个正方体的体积为2853cm,求这个正方体的表面积.(结果保留4个有效数字)2.面积都是50平方米的圆和正方形的周长哪个大?大多少?(精确到0.1平方米)拓展思维借助计算器求下列各式的值,你能发现什么规律?2234+223344+。
最新冀教版八年级上册英语全册教案
备课本冀教版八年级上册英语全册教案班级______教师______日期______冀教版八年级上册英语全册教案教师_______日期_______Lesson 1 Presents from CanadaTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(physics, recent, )2. Ability goals: (1) Useful phrases and structures (one…the other…, make friends,introduce sb. to sb., the same as)(2) Understand the meaning of the text3. Emotion goals: Learn how to express the first day of a new termImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 2 Many faces, One pictureTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(perform, advise, agree, glue)2. Ability goals: (1) Useful phrases and structures (advise sb. to do sth., be up to,agree with, put up)(2) Understand the meaning of the text3. Emotion goals: Learn how to express peopleImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 3 Getting to know youTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(immediately, glad, ahead, hate, either)2. Ability goals: (1) Useful phrases and structures (write down, be glad to do sth., goahead, hate to do/doing)(2) Understand the meaning of the text3. Emotion goals: Learn how to describe their own preferencesImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 4 Best friendsTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(copy, surprise, angrily, lend, embarrassed,enemy, deal)2. Ability goals: (1) Useful phrases and structures (to one’s surprise, lend /borrow, atthe end of, make a deal)(2) Understand the meaning of the text3. Emotion goals: Learn how to describe best friendImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 5 Meet Ms. LiuTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(someone, England, discuss, patient)2. Ability goals: (1) Useful phrases and structures (in front of, feel lucky to do sth.,discuss sth. with sb., be patient with sb.)(2) Understand the meaning of the text3. Emotion goals: Learn how to describe favourite teacherImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 6 Jenny’s weekTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(jeans, pleasure,local)2. Ability goals: (1) Useful phrases and structures (a pair of jeans, have the pleasureof doing sth., invite sb. to do sth.)(2) Understand the meaning of the text3. Emotion goals: Learn how to express own weekImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Unit 1 Review一.短语归纳1.One…the other…一个……另一个 2.make friends交朋友3. introduce … to…向……介绍4. the same as 与……一样5. look for 寻找6. look like看起来像7. be up to 由……定8. agree with 同意……9. put up 张贴10.write down写下,记下11.go ahead 请吧,说吧12. play the violin拉小提琴13. at the end of 在……末14. make a deal达成协议15. in front of 在……前面16. play football踢足球17. a pair of 一双……18. be careful小心,注意19. not … anymore 不……再20. at the same time同时二.重要结构1.advise… to do sth .建议……做某事2.hate to do…不喜欢做……3. sb . spend … (in) doing…某人花费…做什么3.to one’s surprise令某人感到惊讶的是4.enjoy doing sth . 喜欢做某事5.feel lucky to do sth .做某事感到很幸运6.encourage …to do…鼓励……做……7.buy sth . for sb .= buy sb . sth .给某人买某物8.have the pleasure of doing…很高兴做某事Lesson13 I love autumnTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(celebrate, round, however, wonder,thanksgiving )2. Ability goals: (1) Useful phrases and structures (the use of “ in /on / at, a seven-dayholiday, however /but, thank you for…..)(2) Understand the meaning of the text3. Emotion goals: Learn how to describe holidayImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 14 Happy memoriesTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(memory, past, choose, lively, birth, attend,touch)2. Ability goals: (1) Useful phrases and structures (get together, too…to…, It’s fun todo sth., stay in touch with)(2) Understand the meaning of the text3. Emotion goals: Learn how to describe family celebrationsImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 15 A present for Li MingTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(size, fit, anyway, style)2. Ability goals: (1) Useful phrases and structures (would like, try on, What size, theuse of “ another “(2) Understand the meaning of the text3. Emotion goals: Learn how to talk about sizeImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 16 Happy ThanksgivingTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(hug, meal, gathering, conversation,dessert)2. Ability goals: (1) Useful phrases and structures (feel nervous, care for, try to dosth., on this Thanksgiving day)(2) Understand the meaning of the text3. Emotion goals: Learn how to celebrate holidayImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 17 Presents from CanadaTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(post, yet, address, top)2. Ability goals: (1) Useful phrases and structures (on /at the top of, pass sb. sth.,best wishes to…, send sb. to sth.)(2) Understand the meaning of the text3. Emotion goals: Learn how to use English to write postcardsImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 18 Li Ming’s birthdayTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(postman, candle, deep, blow)2. Ability goals: (1) Useful phrases and structures (many thanks for…, be in fashion,It’s time for /to do sth., put up, can’t wait to do sth.)(2) Understand the meaning of the text3. Emotion goals: Learn how to use English to write blessing languageImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Unit 3 Review一.短语归纳1. Mid-Autumn Day中秋节2. National Day国庆节3. have fun 玩得高兴4. get together 团聚,聚会5. Thank you for…为……感谢你6. face to face面对面7. stay in touch with 与……保持联系8. try on 试穿9. give …a big hug 给….一个热情的拥抱10. give thanks to…for…为……感谢11. with one’s help在某人的帮助下12. try to do sth .尽力做某事13. care for 照顾,照料14. best wishes to …给……最好的祝福15. on the top of…在……顶部16. all ready一切都准备好了17. have no luck 未能如愿,不走运18. come on快点19. in fashion 时尚,流行20. think of想起,想到21. turn off 关闭22. make a wish许愿23.pick up 取回24. fit…well非常合身25. far from 离……远26. be decorated with用……装饰二.重要结构1. too…to do sth .太……而不能做某事2.It is +adj . to do sth .做某事是……3. would like to do sth .想要做某事4. send sb .sth .= send sth . to sb .寄给某人某物5. I t is time to do sth ./ It is time for sth .该做某事了6. can’t wait to do sth .迫不及待做某事Lesson 25 I want to be a teacherTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(might, scientist, grow, engineer)2. Ability goals: (1) Useful phrases and structures (It’s +adj. + to do sth., give a talk,would /might)(2) Understand the meaning of the text3. Emotion goals: Express what you will do when you grow upImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Teaching procedureLesson 26 What will I be ?Teacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(page, pilot, fear, height, model, overcome)2. Ability goals: (1) Useful phrases and structures (all around the world, a fear ofheights, take steps to do sth., a type of, stop…..from doing sth.)(2) Understand the meaning of the text3. Emotion goals:Talk about what you will be in the futureImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 27 What’s your adciceTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(advice, number, sentence, eighteen,opposite)2. Ability goals: (1) Useful phrases and structures (make /let /have sb. do sth., theopposite of, give sb.advice, choose sb.to be)(2) Understand the meaning of the text3. Emotion goals: Learn how to express own adviceImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 28 Rich or poor? It doesn’t matter!Teacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(postman, candle, deep, blow)2. Ability goals: (1) Useful phrases and structures (many thanks for…, be in fashion,It’s time for /to do sth., put up, can’t wait to do sth.)(2) Understand the meaning of the text3. Emotion goals: express what makes sb happyImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 29 Our ambition and dreamsTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(fishman, policeman, artist, choice, strict,ambition, punish)2. Ability goals: (1) Useful phrases and structures (be strict with sb. / in sth., give sb.some suggestions, make a choice)(2) Understand the meaning of the text3. Emotion goals: Learn how to use English to express own ambition and dream Important points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 30 A famous friendTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(wish, actor, no matter what)2. Ability goals: (1) Useful phrases and structures (work for, no matter what)(2) Understand the meaning of the text3. Emotion goals: Learn how to describe a famous person Important points: Can use phrases freely to make sentences Difficult points: Master important phrasesTeaching method:Speaking,Unit 5 Review一.短语归纳1. talk about 谈论2. give a talk做报告3. in the future 在将来4. grow up长大5. a fear of heights 恐高6. model planes飞机模型7. adcice diamond 8. play with 和…玩耍9. come true 宝石建议10. run a business经营生意11. on weekends 在周末12. give advice to sb .给某人建议13. hope for希望得到14. some…others…一些…另一些二.重要结构…1. be good at doing sth .擅长做某事2. hope to do sth .希望做某事3. be good/nice/friendly to sb.对某人好4. make sb. do sth .让某人做某事5. stop…from doing sth . 阻止…. 做…6. take steps to do sth . 采取措施做某事7. wish sb .sth .祝愿某人某事8. had better do sth .最好做某事Lesson 37 What’s your hobbyTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary (hobby, trade, garden, spare, earth, stone, collect).2. Ability goals: (1) Useful phrases and structures (go doing, in one’s spare time, beinterested in doing…….).(2) The use of the gerund3. Emotion goals: Learn how to use English to express their own hobbiesImportant points: Can use phrases freely and express hobbiesDifficult points: Master the use of the gerundTeaching method:Speaking,Teaching procedureLesson 38 Hobbies are funTeacher: look-over:Teaching aims:1.Knowledge goals: Master thevocabulary(confidence, postcard,outdoor).2. Ability goals: (1) Useful phrases and structures (have confince in, be confident of,not ont …but also…).(2) Understand the meaning of text3. Emotion goals: Learn how to use English to express their confidenceImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 39 Danny’s hobbyTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(gaint,huge,African,anymore)2. Ability goals: (1) Useful phrases and structures (feel proud, be proud of, be proudto do sth. , thank sb. for sth., not…anymore /any longer).(2) Understand the meaning of the text3. Emotion goals: Learn how to use English to express their hobbyImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 40 What’s Paul’s hobbyTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(break, land)2. Ability goals: (1) Useful phrases and structures (be made of / from, do /deal with,give prizes for… / to sb.)(2) Understand the meaning of the text3. Emotion goals: Learn how to use English to express their hobbyImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 41 Show and tellTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(performance,common)2. Ability goals: (1) Useful phrases and structures (go through, It’s sb’s turn to do sth.,take …out of…)(2) Understand the meaning of the text3. Emotion goals: Learn how to use English to express their hobbyImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Lesson 42 The new clubTeacher: look-over:Teaching aims:1.Knowledge goals: Master the vocabulary(real, support, daily)2. Ability goals: (1) Useful phrases and structures (send sth back to sb., bring sth. tosb., take good care of(2) So+助动词/be动词/情态动词+主语3. Emotion goals: Learn how to use English to express their hobbyImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Unit 7 Review一.短语归纳1. in one’s free/spare time 在某人的空闲时间2.take up开始从事3. trade sth . with sb . 与某人交换某物4. all kinds of各种各样的5. be interested in 对……感兴趣6.feel proud感到自豪7. have confidence in 对……有信心8. some more 再来些9. a photo of 一张……的照片10. be made of由……制成11. the best-built rocket最佳制作火箭12. parking lot停车场13. up and down 上上下下14. so much这么多15. put…on its side 将沿侧面放16. used to过去常常17. take…out of…从……拿出……18. pay sb . a visit看望某人二.重要结构1. go doing去做某事2. one of the +形容词的最高级+可数名词的复数形式最……之一3. How about doing sth .? 做某事怎么样?4. Why not do sth ? 为什么不做某事5. give up doing sth . 放弃做某事冀教版八年级上册英语全册教案2教师_______日期_______Unit 1 Me and My classLesson1Back to School!Teaching objectives:1. Graspthemastery vocabulary and phrases.2.Make the students understand the meaning of the text.3.Learn something about an e-mail written by English.After learning this lesson,the students can write their own e-mails. Teaching Aims1.Knowledge goals: Master the vocabulary(physics, recent, )2. Ability goals: (1) Useful phrases and structures (one…the other…, make friends,introduce sb. to sb., the same as)(2) Understand the meaning of the text3. Emotion goals: Learn how to express the first day of a new termImportant points: Can use phrases freely to make sentencesDifficult points: Master important phrasesTeaching method:Speaking,Teaching progress:Classopening:Introduce the topic of this unit.Key steps:Step1. Ask the students to disc uss the question in“Chat Show”What did you do in your summer holiday?Step2.DictationDictatethesewords: back, be back, grade, student, pupil, class, have,have lessons /classes, more, cousin, brainStep3. Present new sentencesbe back/be back homee.g.I am back.T: Ask one student “Which Grade are you in this year?”S: I am in Grade 8 this year.T:How many students are there in your school?S: There are about 900 students in my school.T: How many pupils are there in your class?S: My class has 50 pupils.Then the teacher makes the students do pair works, make sure they canuse these sentences to ask and answer.Write “We have our class in one room and the teacher s come to us.”Explain the meaning of this sentence to the students.Step4. Project some questions on the big screen1. How many new classmates does Danny have? What are their names?2. What advice does Li Ming give Danny on how to start a conversation with Sandra?3. Li Ming has a new subject this year. What is it?4. What will Li Ming do to prepare for his class tomorrow? Why?Step5.Project some sentences of the second e-mail,have the students listen to the tape and decide them “True” or “False”1. It wasn’t fun to get an e-mail from China. ( )2. This year, school begins at 8:30. ( )3. Every teacher has a different classroom. ( )4. Mycousin Brain arrives from the U.K on Tuesday.( )5. Brain is fourteen years old. ( )Then tell the students the ways to write and send an e-mail.Step 6. Language points.1. Back to school. 返回学校。
冀教版八年级上1—4单元教案(冀教版八年级英语上册教案教学设计)3232
冀教版八年级上1—4单元教案(冀教版八年级英语上册教案教学设计)Unit 1 Me and My ClassLesson 1 Li Ming Is Back to SchoolⅠ.Teaching content:1. New words and phrases: grade, student, class, pupil, cousin; be back, have lessons/classes2. Introduce yourself and your schoolⅡ.Teaching goals1. Learn new words: back grade, student, class, pupil & cousin2. Make sure the Ss can introduce themselves and their school3. Talk about the differences between schools in China and other countries.Ⅲ.Key points:1) Some new words and phrases2) Introduce a school by mailⅣ.Difficult points: Compare schools in China and Canada Ⅴ.Preparation: some word cards, picturesⅥ.Teaching resources: recorder, pictures or cardsⅦ.Type of the lesson: listening and speakingⅧ.Teaching procedure1: Class opening1)Teacher’s and Ss’ self-introductions.T: I’m your (new) English teacher from today. My name is …. You can call me Mr./Ms.x. I’m glad to learn English with you. I hope to be your friend, so I want to know you now. Please introduce yourself to me. Who wants to be my first friend?S1: My name is Wang Wei.T: Good, thank you Wang Wei. You are a handsome boy..S2: My name is Li Xiaohua.T: Very good. Glad to get my second friend. Thanks, Xiaohua. Your red skirt is so beautiful. I like red very much. Where are you from?…(The teacher can ask Ss some other questions, such as: How old are you? Do you like English? What’s your favorite color? etc. but do remember to praise each student for whatever he/she says in English.)2)Lead in tod ay’s new lessonT: After you introduced yourselves, I have known some of you. Now I want to know something about our school. Who can tell me? Is it big?S3: Yes, It’s very big.T: oh? How big is it?S4: Every grade has 8 classes.T: Wow, yeah. It’s quite big. Then we have 24 classes (the teacher can pause a little here , waiting for the Ss speak together) altogether. Very good, Who can tell me how many students in our class?S5: Forty-eight.T: Thank you, S5. You know our class well. How many girlsin our class?S6: twenty-five.…T: Thank you all for telling me about our school. Who knows schools in some other countries? For example, in Canada, their schools are bigger or smaller? You can guess the answer. Who wants to have a try?S7: bigger?T: Good! A nice try. Thanks.S8: I think, smaller.T: Good, it’s a different answer. Thank you. We’ll get the answer after we learn this lesson. Please turn to Page 2 of your textbook. We have more questions to discuss.2. New lessonStep 1: Ask the S s to discuss the questions in “Think About It.”Take the first question as an example:T: Have you changed over the summer holiday? S9, what about you?S9: Yes, Mr/Ms.x. I’m taller. I often went swimming with my brother.T: Swimming is good exercise in summer. What about others? S10: I’m thinner but taller. I played football everydaywith my friends.S11: I’m sorry to say I’m fatter now. I like watching TV at home in the summer holiday.…Step 2: Listening and answering:A) Listen to the tape (of the first e-mail) with some questionsT: We’ve talked about our school and class. Next, let’s listen to Li Ming’s e-mail then you can know schools in Canada are bigger and smaller. Please listen carefully and answer the following three questions:1) Where did Li Ming write the letter/mail?2) How many pupils are there in Li Ming’s class?(Play the tape )T: Jenny is in Canada. Do you think schools in Canada is bigger or smaller?Ss: (together) smaller.T: Very good. S12, answer question 1, please.S12: (Li Ming wrote the letter) In China.T: Good, S13, How many pupils are there in Li Ming’s class? Do you know “pupils”? Yes, “pupil” means student.S14: There are fifty pupils in his class.T: Right, very good.B) Listen to the tape (of the second e-mail) and answer the following question. (Do the same as in section A)Who will come from the U.K.?Step 3: Reading and discussingA) Fast readingT: Read the two e-mails fast and silently. Then let’s discuss more about them. Here are some more questions:1) Who is the e-mail from and to?2) What can you learn from the two e-mails?3) Do you like schools in Canada?4) Do you going from room to room for your class? Is it good exercise?5) Who is Brian in the second mail? How old is he?…B) Second reading and further discussingT: Read the text a second time. Then we’ll have a further discussion in groups of 4 students. The question for you is: What are the same or different things between the schools in China and Canada. I’ll give you 5 minutes t o discuss. Then you should report your discuss to our class. (Five minutes later, collect the result of their discussion.)T: group 1, what are the same things between the schools in China and Canada?S15(from group 1): There are classrooms in all the schools. T: Good! Anything else? Group 2?S16 (from group 2): There are many teachers.T: Very good! What’s the different things then?S17(from group 3): Schools in China are bigger.S18(from group 4): Every teacher has a different classroom in Canada.S19(from group 5): Students in Canada go from room to room for their lessons. Students in China have class in one room.S20(from group 6): In Canada, there are more teachers in their schools.School begins at 8:30 in Canada, later than in China.…Step 4: Answering questionsEncourage the Ss to ask questions about the text, including the meaning or usage of the new words and phrases in this lesson. Explain to the students and make notes on the blackboard. (see the explanations in the attached reference materials)Step 5: “Let’s Do It” sectionT: It’s our new school term. It’s our first lesson today. Then let’s talk about the new term. Look at the questionsin “Let’s Do It!” and talk more.3 question you’ll get: What is the same in the new term? What will be different? What will you do differently?Step 6: Homework1) Write an e-mail to your friend2) Finish off the exercises in the activity book3. Class closingSum up this lesson and end it.T: Today we learned two e-mails. There are some new words and phrases we should remember: grade, student, class, pupil, cousin; be back, have lessons/classes. We also know about the differences between schools in China and Canada. Please practise writing an e-mail to your friends after class and finish your homewo rk. That’s all for today.lesson 2 Many Faces, One PictureⅠ.Teaching content:1. New words and phrases: photo, look like (fourskills) ; photograph, wish2. Likes and dislikes3. The Simple Present Tense (positive and negative forms)Struct ures: I like…/ I don’t like…Ⅱ.Teaching goals1.Master some new words and phrases: photo, look like, take pictures/photos2.Get to know some other words: wish, photograph3.Learn to express likes and dislikes1. Master the negative form of the Simple Present Tense Ⅲ.Key points:1) look like2) likes and dislikesⅣ.Difficult points: Express one’s dislikes: I don’t like…Ⅴ.Preparation:1) One photo of you2) Some real things such as a banana, a book and some clothes3) Some cards with words of describing yourself4) A big piece of paper and glueⅥ.Teaching resources: recorder, tape , some cards, a big piece of paperⅦ.Type of the lesson: listening and speakingⅧ.Teaching procedure1: Class opening1) Greet the students and check the homeworkT: Hi/Hello/Good morning, everyone/class! How are you today? It’s a beautiful day, isn’t it?Ss: Yes, it’s sunny.T: Ok, Let me check your homework first.(a few minutes later)2) Prepare for the new lessonT: let’s try to remember wha t we learned yesterday. We talked about Li Ming’s school. In this lesson, we will talk about something new.(Take out the banana, book and a piece of clothes of the bag)T: Can anyone guess why I have brought these things? Whatis the connection between these things? Please guess. Look, this is my red blouse, I’ve told you I like red very much. And the book, it’s my birthday present last year. Yes, this is a banana. I often buy bananas because I like eating bananas.Ss: You like all of them!T: Very good, you got it!2. New lessonStep 1: lead in(Show the three things )T: These are the things I like best. Next I want to know more about you.Step 2: Discussion before the new lessonT: Look at the questions in “Think About It!” and discuss about them.(introduce the questions to the Ss and give them five minutes to discuss)T: All right! Time for me to know how well you know about your friends. S1, who is your best friend?S1: Wang Gang.T: What do you know about him?S1: He likes basketball very much.T: What about you, S2?S2: My best friend is my cousin, she likes school.T: Good! S3, talk about the favourite photo of yourself, please. When was it taken?S3: Just in the summer holiday.T: Good! What about you, S4? When was your favourite photo taken? And where?S4: It was taken in Beijing last year. My father took the photo for me.Step 3: Discussion about the picture in the textbookT: Look at the picture in your books and let’s talk about it: what is in the girl’s hands? What is she doing? (introduce the word “wish” to the students and make sure they know the meaning of “photo”)Step 4: Further discussionAsk about the title of this lesson: Why is the lessoncalled “Many faces, One picture?”Step 5: listen and find the answerAsk the Ss to listen to the tape and find the right answer; the answer is in the text. Check the answer with the Ss: Answer: Everyone brings a photo of him or her. We put them together and make a big picture of our class. There are many faces of the students in the big picture.Step 6: Project 1: Make a class pictureMake sure the Ss understand what they must do in the project. Explain what a collage is. (in Chinese if necessary) A collage is a picture made of many little pictures.T: Draw a picture of yourself if you don’t have a photo. Write down at least three sentences about yourself on a small piece of paper. That’s your name card. Of course, our cards are better.(After a few minutes, Ask several Ss a few questions tohelp them describe themselves.) The questions can go like this:1. What is your name?2. How old are you?3. How tall are you?4. What are you wearing in your picture or photograph?5. What do you like to do?6. Where do you live?(The class will make a collage.T: First, work in pairs please! Ask your deskmate questions about themselves. Then ask other members in your groupsimilar questions.(Let the Ss find their own partner to practise. Using the sentences in their cards. Encourage the Ss to read whatthey have written down. Then use their own words.)T: Now, it’s the time for us to introduce your partners to out class now. S5, introduce your classmates, please.(After the Ss’ introductions, ask them to glue the pictures to a big sheet of paper for the whole class. Several Ss can glue at the same time.)At the end, the class has a collage! Post the collage inthe classroom or the halfway for everyone to see.Step 7: Homework1) Read the text in Lesson 2Do the remaining exercises in the activity bookLesson 3 Getting to Know You!Ⅰ.Teaching content:1.New words and phrases: Miss, married/be married, either, glad, really, also, dislike, hate, interest, violin, music, comb2.Likes and dislikes2. I don’t know her.She doesn’t like purple.What does she hate to do?What foods do you love?Ⅱ.Teaching goals1.Learn the usage of the following new words: Miss,married/be married, either, glad, really, also, dislike, hate, interest, violin, music, comb2. Learn how to express likes and dislikes (oneself and others)3. Consolidate the usage of the negative question form of the Simple Present TenseⅢ.Key points:I want to talk to SandraI don’t know her, either.I like donuts bestⅣ.Difficult points: Express one’s dislikes: I don’tlike…,either.What do you hate?Ⅴ.Preparation:1) Draw some pictures or find some pictures for the characters in this lesson: Danny, Jenny, Miss Cox and Brain.2) Write down the key new words on cards.1) A rubber toy of dinosaurⅥ.Teaching resources: recorder, tape , word cards, some picturesⅦ.Type of the lesson: listening, speaking and readingⅧ.Teaching procedure1. Class opening1) Greet the Ss in everyday English. Help them respond in correct way.2) Correct the exercises of activity books3) Ask “Who’s on duty?” Listen to the students’ report. They may talk about the date, the weather, their favourite colour, book , sports or film. Give them words and expressions when necessary to help them.4) Draw a picture “an unhappy artist” on the blackboard.T: Look at the “long” face of t he artist. He is unhappy, yes? When is he unhappy? Guess the reason, pleaseGive the Ss a few minutes to talk about the reason in order to start the new lesson.2. New lessonStep 1: lead inT: Do you like watching TV? I like some programs very much.F or examples, “Talking Straight” (shihua shishuo ) and “Sons and Daughters of the East” (dongfang zhi zi). Do you like them? The project you are going to do is to interview each other. You can ask your classmates many questions just like the hosts or hostess do in the TV programs, such as Wang Xiaoya, Li yong and so on. Of course, you have to use English! But it’s fun! I’m sure you will like it.Step 2: Listen and find use informationT: Listen to the tape please and find the answer of this question: Who does Danny want to interview?(show the rubber dinosaur and draw some “tears” on its face)T: These are Danny’s tears. Do you like dinosaurs? (Yes!) but Danny is unhappy now. Do you want to know the reason? Read the text on Page 4 with the title of “She’s soBeautiful!”Step 3: Read and discussAfter the Ss read the text fast and silently, let the Ss discuss the following question:Why is Danny scared? ( Because he wants to talk to Sandra) Do you think Danny and Sandra will become good friends? Why? (Yes, they will become good friends. Because girlslike dinosaurs and they have a nice talk to each other) What is Sandra like? (She’s beautiful.)Check the answers with the whole class.Step 4: Further reading and further discussionT: Read the text a second time and have a furtherdiscussion about it. Answer more questions about it.1) Do they like Miss Cox’s surprise in their English lesson?2) Why can the students call their English teacher “Miss” Cox?3) What colour does Sandra love?4) What does Sandra dislike?5) What are Sandra’s interests?Step 5: Explain some new words and phrases (see Text Explanation of Lesson 3)Step 6: Project 21) T: It’s a interview project. So you can be the host or hostess now. You can ask any question that you are interested in. Let’s prepare some small cards for the interview first.2) Guide the Ss to make interview cards like this: Interview Chart 1Name What He/She Loves? What He/She Hates?Interview Chart 2Name What He/She Loves to Do? What He/She Hates to Do?Help the Ss remember some useful words for the charts. such as “food” , “clothes”, “animals” and “colours”. List the verbs that students know to fill in the charts.Examples of possible questions and answers:Q: What is your favourite ?A: My favourite is .Q: What do you love/hate to do?A: I love /hate to .Q: Do you like to ?A: Yes, I like to / No, I don’t liketo .Q: What do you like best about your school?A: I like best.Q: Who is your best friend?A: is my best friend.(Have Ss find a partner and take turns interviewing each other.)T: Ask your partner those questions and write down their answers. Then fill in your charts.(If time permits, collect the Ss answers and talk about the results of their interviews.)3. Class ClosingT: Practise your likes and dislikes after class, It’s your oral homework and don’t forget the written homework in your activity books. Let’s call it a day. Bye, boys and girls! Lesson 4 On a School DayⅠ.Teaching content:1. New words in this lesson:A:jeans,weekend, wool,cotton, blouse, be made of (four skills) B:round/allyear around,iron,tidy (get familiar with them)2. weather and clothesⅡ.Teaching goals1. Master the news in this lesson: jeans,weekend,wool, cotton, blouse, be made of2. Talk about weather and clothes3. Learn the English songⅢ.Key points:He wears pants on a school day/ blue jeans on the weekend Something different all year aroundⅣ.Difficult points: Wear different clothes in different weathersⅤ.Preparation:1) Prepare some clothes in different seasons: some in winner against cold,some in summer for keeping cool;2) Some color chalks; Some pictures with different clothes3) Draw some sketches of typical clothes in 4 seasons of a yearⅥ.Teaching resources: word cards, some pictures,some clothes,slide projectorⅦ.Type of the lesson: listening, and singingⅧ.Teaching procedure1. Warming up(Singing “Good morning ”song, whose tune is from “Happy birthday ”song. Teacher entered the classroom. )T: Do you like singing? Who can sing a song for us? Whatabout English songs? Introduce some famous but simple songs t o the Ss such as “Twinkle stars”, “Jingle bell”, “Mary has a little lamb”, etc. Who can sing a song for us?(Maybe most of the Ss can only sing some Chinese songs. It doesn’t matter, praise the Ss who have sung to get them excited. It’s good for today’s le sson)T: Yeah, you can sing Chinese songs very well. Today let’s learn an English song, then you can sing to your parents in future. But what kind of songs do you like?2. New lessonStep 1: lead inT: What’s the weather like today? What clothes are yo u wearing on school days or on the weekend? There’s a song about it. Would you like to learn the song?(show the Ss the clothes and the word cards to prepare for learning the new words about clothes. Make sure they know the meaning of the song)Step 2: A quick review about clothes wordsReview some old words for clothing, then learn the new words in this lesson: blouse, jeans, be made of, cotton, woolStep 3: Read and understandT: Let’s read the lyrics of the song. Pay attention to the new words we learned just now. Notice the rhyme, rhythm and repetition in the song. (It’s a good preparation forlearning the song fast)Step 4: Explanation1) Explain the meaning of the lyrics, especially some sentence structures. Also help Ss to group words in the song. For instance: He wears pants / on a school day, Blue jeans / on the weekend, something different / all year around.1) Ask some questions about the song to make the Ss under it wellWhat does he wear on a school day? (Pants)Does he wear pants every day? (No, he wears blue jeans on the weekend)What is his clothing made in winter? (wool)Does he always wear the same clothes all year around? (No, he wears different )Step 5: listen and learnT: Now let’s listen to tape. You can just listen for the first time to get the tune. Then sing in a low voice with the tape.Step 6: Practise singingAsk the Ss themselves after having listened to the songsfor several times. Then listen to the tape once again.Select one particular student who sings well to be an example or lead to sing for the other students.Step 7: DiscussionDon’t miss the “speech bubbles”! Talk about them with the students. Ask questions like these:Do boys wear dresses? (No, girls wear dresses.)What’s in the girls hands? ( A sweater.)Do you love sweaters?Do you like its colour? What’s your favourite colour?3. Ending class1) Homework: finish the remaining exercises in activity book2) Learn the song after classPrepare another song to share with class next lesson for singing.Lesson 5 The Best ClothesⅠ.Teaching content:1. New words and expressions:A:anymore/not…any more,gray=grey, paint , very much, voice, silly, classmates(four skills) B:backpack(get familiar with them)C: names of persons: Peter, Gina(read)2. Likes and dislikes about clothesⅡ.Teaching goals1. Learn to use the new words and phrases: anymore/not…any more, gray=grey, paint , very much, voice, silly,classmates2. Learn to make comments on clothes3. Sentences structures about comments on clothesⅢ.Key points:I don’t like this pair.What did you do to your runners?They look silly.Krista could not think of an answer.Ⅳ.Difficult points:1) The right attitude towards new clothes2) be friendly to classmatesⅤ.Preparation:Prepare a new pair of shoes and old ones and a big paperfor a sketch of a dressⅥ.Teaching resources: a big piece of paper, some marks and paints, a pair of old shoes.Ⅶ.Type of the lesson: reading and comprehendingⅧ.Teaching procedure1. Class opening1) Make the class warm by s inging the song “On a school Day” together with the students.2) Check up their homework in the activity book. Give them some explanation when necessary2. New lessonsStep 1: Lead inT: Today let’s continue to talk about clothes. Look at my old shoes. Oh! They are gray, really too old. I like new clothes and shoes. What about you? I also have some nice pictures here for fashionable clothing. (show the pictures to the students.)Step 2: Discussion in “Think About It!”T: We’ve got some questions to discuss in “Think About IT!” Read though all the questions and discuss with your partners. I’ll give you 5 minutes in this section.(Five minutes later, check out Ss’ results of discussion) Step 3: Listen and get key pointsT: Listen to the recorder, please. And answer two questions after that.Q1: Who told Krista to paint her shoes? (Peter)Q2: Who said Krista’s shoes were silly? (Gina)Step 4: Read and understandT: Read the text fast and silently by yourselves then have a discussion about the story. There are more questions for you:1) What do Krista’s runners look like? (They are old and gray.)2) What does Krista do to her runners? (She paints her runners with marks and paints.)3) Is Gina Krista’s good friend? (No, Krista doesn’t like Gina.)4) Why does Gina laugh at Krista? Is it right? (Because Krista paints her shoes and they look silly. No, it’s wrong to laugh at others.)Step 5: Further discussionT: Discuss the story more deeply. Think about the two questions:1) If you were Krista what would you do? (suggested answer1: If I were Krista I wouldn’t paint my shoes. I will just keep them clean and take good care of them. We feel very comfortable when wearing old shoes. Suggested answer 2: I would also paint my shoes. Because I t hink it’s funny to make old shoes have a different color.)2) If you were Gina what would you say when you see Krista’s painted shoes? (suggested answer 1: If I were GinaI would say :”Hi, Gina, you did a good job. Your runnerslook so nice now.” sugg ested answer 2: If I were Gina I would say :”Please buy a pair of new shoes. Old one arestill old after painted ”)Step 6: Meaning of the storyT: Read the text once again, please. Try to get the meaning of the story. Then discuss what’s the right attitud etowards appearance and classmates.Step 7: “Let’s Do It!” sectionT: Let’s see what we should do in this part.11) Find the reason why Krista wants to cry. Does it recall the similar feeling when you feel embarrassed? Did the feeling last a long time?2) Guess how the story will go without reading the second part in the Reader. Read it for your partner and check whether your guess is right or wrong.3. Class closingT: let’s see our homework for today.1) The third reading in the reader2) Other exercises in the activity book3) The next reading in the students bookSometimes we not only get fun from some stories but also significant experience. “Reading makes a wise person.” So let’s enjoy reading and leaning. Have a nice day. Bye for now.Lesson 6 Meet Ms. LiuⅠ.Teaching content:1.New words and phrases: A: Mr./ Mrs./ Ms. , special, husband, piano, singer, nervous. ( used freely) B: finish, introduce, English (for oral English)1. Introduction of a teacherⅡ.Teaching goals1. Master the new words: Mr./ Mrs./ Ms. , special, husband, piano, singer, nervous.2. Learn how to introduce a teacher.3. Some useful expressions: using Mr./Mrs./Ms. in thecorrect wayⅢ.Key points:Now he is ready to introduce someone to the classI talked to someone very special.Walking to school in January.Don’t be nervous.Ⅳ.Difficult points: How to present a good introduction of ateacherⅤ.Preparation:1. Write down the key new words on cards.2. Prepare something in our daily life or draw some pictures3. Find some photos of famous hosts or hostesses in magazines, like Wang Xiaoya, Li Yong and so onⅥ.Teaching resources: photo, word cards, some pictures, recorder and slide projectorⅦ.Type of the lesson: speaking and practisingⅧ.Teaching procedure1. Warming up1) GreetingsT: Hi, class! Good morning. How are you doing today? It’s September now, not hot and cold. I like autumn in the four seasons of year. And remember we need to wear different clothes in different seasons.2) A brief review of yesterday’s lesson3) Duty reportT: Who’s on duty today? Introduce the weather to us today. And describe what clothes your classmates are wearing.2. New lessonStep 1: Lead in(Show the photo of Wang Xiaoya)T: You like her very much, yes? Me, too! Would you like to talk to her? We’ve learned how to interview someone.Imagine you’ve interviewed Wang Xiaoya. And then you are asked to introduce her to your class. Do you know what we want to know about her?Guide the Ss to know the way of introducing someone with some questions:1) Where does she live? (She works in CCTV, so shelives in Beijing.)2) What does she do? (She a good hostess of “Quiz Show” on TV.)3) What is she good at? (She is good at hosting.)4) How is she doing her work? (She works very well. Others even learn from her and her program)5) How do you like her? (She always smiles and I like her very much.)Step 2: key point: introduce how to use Mr./Mrs./Mscorrectly(Show a photo of a family)T: Look at this photo, please. It’s a photo of the famous host of Li Yong. Who is the lady besides him? Yes, his wife. And this little girl is their daughter. I can call Li Yong “Mr. Li”. Do you know what we can call his wife?Right! “Mrs. Li”. So wha t about his daughter?(Let the Ss try to guess. Maybe some of them know the answer. Then guide them to be aware of the differences of the three words.)T: Good, so let’s summarize the usage of the three words: We use “Mr.” before his family name. No matter he ismarried or not. But we only call a married woman “Mrs.” Right? Then what about a girl, an unmarried one? Yes. Very good. We call a girl “Miss”. We can call a lady “Ms.x” if we don’t know whether she is married or not.Step 3: Discussion of questions in “Think About It!”T: There are some questions for us to discuss on top of Page 8. Read them and think about it. You can discuss with you partners. Then take turns to speak for a introduction. Step 4: Listen and useful informationT: Li Ming will talk on the tape. He also introduced a teacher, Ms. Liu. Listen for the first time and get the answer to this question: How long has Ms. Liu lived in Shijiazhuang? (For two years)Step 5: Further study of the textT: Read the text by yourselves, please, and try to get the information about Ms. Liu as much as possible. Ask me what you can’t understand.Step 6: Discussion and understandingGuide the Ss to discuss the text about Ms. Liu. Check them whether they can understand the text well. The following detailed questions are available:1) How does Ms Liu’s students like her? ( Her students like her very much.)2) How long has she been an English teacher? ( For seven years.)3) Does she always live in China? (No. She once went to school in London to learn English.)4) What food does Ms. Liu like? (Dumplings)5) What’s her favourite animal? (Monkeys)6) Does she have many interests? Give us some examples. (Yes. Ms. Liu has many interests. She likes swim , thepiano and she sings well.)7) What does Ms. Liu hate to do? (She hates walking to school in January, because it’s cold.)Step 7: card-makingT: After the discussion, we have know Ms. Liu very well. Now take out a piece of paper. Let’s make a personal card for Ms. Liu.(Present the card by using the slide projector)Name Teaching English Living in Shijiazhuang For English Likes Dislikes。
冀教版本初中八年级学习教学英语导的学案上册的
花牛镇白家河学校2014-2015学年度第一学期八年级上册英语导教案本学年课程标准大纲领求本册教课目的一、语言技术要求1语音方面:听闻读写(略见四,五级学持续稳固学习音标,掌握英标,练习习标准)稳固用音标拼读单词,学习连读,重申重二、语言知识语音读,与起落调!依据读音规则和音标拼读单词2词汇方面:语法:掌握一般此刻时,一般过切记不规则动词表,100-150个短语去时和一般未来时的被动语态。
及固定搭配,认识各样词性与用法背会掌握动词不定式,动名词等非500-700个常用单词,认识理解名词属格、谓语动词等冠词,反身代词,形容词的比较级,动词三、学习策略不定式,掌握英语必定的学习方法学会3时态方面:听闻读写的英语基本学习策略在(一般此刻时和一般过去时,四、感情意识一般未来时和过去未来时,此刻进行时知道学习英语的,用途与重的)基础上学习此刻达成时、过去达成时要性有明确的学习目标,和过去进行时五、文化意识4句法方面:认识中西方文化的的不一样,有学会五种基本句式,认识宾时间状语从句文化意识与文化容忍度和原由状语从句,宾语补足语教本册教科书共八个单元,48课。
课文内容以八个话题睁开,分别材是我和我的同学,我最喜爱的科目,家庭聚会、我的街坊、我的未来、分交通、兴趣喜好、庆贺自我。
环绕这八个话题在本册书中睁开句子为析中心的学习。
但归纳起来可简化为四个话题,我——学校——家庭——社会。
切合学生的认知发展规律,切近学生的平时生活实质,激发了学生的社交潜力和学习兴趣。
学本班共22人,男生8人,女生14人,学习能力与学习水平参情差不齐,个别女生学习态度正直,学习成绩较好女生如杨茜茜,李兰雪,分杨婵云,白娜,杨艳峰。
男生董源学习能力较强,可是基础一般。
其析余16人中学习态度比较扎实的有白冰燕,杨欢欢,白斌杰。
学习不是很扎实学习效率较低的有王雨雨、董鹏源、李荣荣。
杨子涵。
学习态度不正直,学习成绩特别差的有董倩,董翠萍王博辉、白文博、董建科、师喜龙、李尹杰、董文伟,董云霞。
冀教版初中数学八年级上册全册学案(1)
冀教版初中数学八年级上册全册学案(1)冀教版八年级上新课标学案第1三章一元一阶不等式与一元一阶不等式系统第一节不等式学习目标1体验从特定问题场景建立不平等模型的过程,以进一步发展学生的符号感。
2.理解不等式的含义,认识到不等式是表示相似量之间关系的重要数学模型3.体会现实生活中存在着大量的不等关系,学习不等式的有关知识是生活和工作的需要.指出:判断一个表达式是否是一个不等式就是看公式是否包含一个不等式符号,所以答案是(1)(2)(4)例2列不等式:(1)X和的三倍1的差是非正数.2课前预习方案?自主学习1.用等号或不等号填空:⑴0_____-32;⑵3.3_____二23、 102(2)a的2倍与b的差不小于4.(3) X和y的平方和不能小于5(4)。
小红家有三口人,人均住房面积不足20平方米,则她家的住房面积x平方米可表示为.点拨:不等式反映的是代数式之间的不等关解决这类问题的关键是把握关键词,明确不平等关系的解决方法:(1)3x-⑶a_____0;⑷v3-xw_____vx-3w.2.如果零件的长度表示为l=50±0.3,则该零件的长度l的范围为____________________,≥, ≤, ≠. 2.阅读不平等;例如:“>”被解读为大于。
3不等号的含义:例如,“>”表示左边的金额大于右边的金额1x≤0;(2)2a-b≥4;2x22(3)x+y≥5;(4)<20.3例3.用a、b两种原料配置成某种饮料,已知这两种原料的维生素c含量及购买这两种原料的价格如下表:维生素C(单位/kg)原材料价格(元/kg)a种原材料5007a种原材料2022课堂学习计划知识结构1不平等的定义:由不平等符号连接的公式称为不平等。
2列不等式:根据本主题中的不等关系级数推导相应不等式的过程称为列不等式。
3判断使不等式成立的值的方法:将数值代入不等式的左、右两边,如果合不等号所表示的不等关系,则数值就为所要求的数值;反之,不是.典型例题例1.在下列表达式中:(1)-2<0,(2)x-3y22≥1,(3)5a+1=0,(4)7x+3≠y,(5)a+2ab-b是不等式的________________________(只填序号).现在我们准备了12公斤的这种饮料,其中至少含有4000单位的维生素C。
冀教版英语八年级上册全册精品教案【新教材】
冀教版英语八年级上册全册精品教案【新教材】备课书纪教版初三第一册英语全书教案课_ _ _ _ _ _ _ _老师日期_ _ _ _ _ _ _ _11单元1 Me和我的班级2569教学目标:1。
掌握掌握词汇和短语。
2。
让学生理解课文的意思。
3.了解一些用英语写的电子邮件。
学完这一课,学生们可以写自己的电子邮件了。
9教学目标。
知识目标:掌握词汇(物理,最近),2。
能力目标:(1)有用的短语和结构(一个…另一个…,交朋友,介绍某人。
对某人。
,同)(2)理解文本3的含义。
情感目标:学习如何表达新学期的第一天要点:可以自由使用短语造句难点:掌握更重要的短语教学方法:说,教学进度:开班:介绍本单元的主题。
关键步骤:步骤1。
让学生讨论“聊天秀”中的问题,你暑假做了什么?第二步。
听写听写这些单词:背,回来,年级,学生,学生,班级,有,有课/课,更多,表弟,大脑步骤3。
现在新句子回来了。
T:问一个学生“你今年几年级?”我今年在八年级。
你的学校有多少学生?我们学校大约有900名学生。
老师:你们班有多少学生?我的班级有50名学生。
然后老师让学生做结对作业,确保他们能用这些句子提问和回答。
写“我们在一个房间里上课,老师来找我们。
”向学生解释这个句子的意思。
2步骤4。
在大屏幕上投影一些问题1。
丹尼有多少新同学?他们叫什么名字?2。
李明对丹尼如何和桑德拉开始对话有什么建议?3.李明今年有了一个新科目。
什么事?4。
李明将做什么来准备明天的课?为什么?步骤5。
设计第二封电子邮件的一些句子,让学生听录音,并判断它们是“真”还是“假”。
从中国收到一封电子邮件并不好玩。
()2。
今年,学校八点半开始上课。
()3。
每个老师都有不同的教室。
()4。
我表哥布雷恩星期二从英国来。
()5。
大脑十四岁了。
他们告诉学生写信和发电子邮件的方法。
回到学校。
当(1)back用作副词时,它的意思是“在(到)同一个地方;回到它的位置”我将在七点钟回来。
(2)back作为名词的意思是“back ”;后面”我的背很疼。
冀教版八年级生物上册教学案与练习全集(全册)
课题:第三单元第一章第一节种子萌发的过程第1周第1 课时教学目标:1举例说出种子的结构。
2说出种子的各结构在种子萌发中的作用。
3描述种子萌发的过程。
4认同“人与自然和谐发展”观点。
通过参与种植、管理植物的活动,增强爱护植物的情感重点:种子的各结构在种子萌发中的作用难点:描述种子萌发的过程教学过程预习检测:各种植物的种子,尽管形状、大小、颜色不一样,但是却有大致相同的结构,都有和,胚是新植物的幼体,是种子的主要部分,它由、、、构成。
知识点拨:种皮:保护菜豆种子的结构胚芽:发育成茎和叶双子叶植物的种子胚胚轴:连接根和茎的部分胚根:发育成根子叶:提供营养 2片果皮和种皮胚芽玉米粒的结构胚胚轴单子叶植物的种子胚根子叶 1片胚乳:贮存养料测一测1、播种时要选取粒大饱满的种子,由于种子的或是储存营养的结构,只有发育完全、的种子能发育成健壮的幼苗。
2.已被虫蛀过的种子,一般不能萌发,其主要原因是( )A.种皮破损,无保护作用B.胚被虫蛀破损,无生活力C.外界条件不适宜D.种子因感染病毒而失去生活力4.粮仓中存放了十年的小麦种子虽给予适宜条件,一般也不能萌发,其原因是( )A.种子仍处于休眠期 B.种子已过寿命期而死亡C.种子的种皮太厚 D.种子因受抑制而不能萌发5.保存种子的适宜条件是( )A.低温干燥 B.高温干燥C.高温潮湿 D.低温潮湿6.在菜豆种子的萌发过程中,首先突破种皮的结构是 ( )A.胚根 B.胚芽 C.胚轴 D.子叶7.在菜豆种子的结构中,能发育成幼苗的茎和叶的是 ( )A.胚根 B.胚芽 C.胚轴 D.子叶8.在菜豆种子和玉米种子的萌发过程中供给胚根、胚轴和胚芽营养物质的结构分别是( )A.子叶和胚乳 B.胚乳和子叶C.子叶和子叶 D.胚乳和胚乳9.种子的休眠有利于 ( )A.营养物质的积累 B.吸收各种营养C.渡过恶劣的环境 D.营养物质的制造能力提高10、解剖种子的结构,发现子叶是连接在结构上的。
(冀教版)八年级数学上册(全册)精品导学案汇总
(冀教版)八年级数学上册(全册)精品导学案汇总反证法学习目标:1.了解反证法的意义及用反证法证明一个命题是真命题的一般步骤.2.学会运用反证法证明有关命题.学习重点:反证法的一般步骤.学习难点:运用反证法证明有关命题.自主学习知识链接1.在证明一些命题是真命题时,一般采用__________证明的方法.2.在证明与图形有关的命题时,一般有哪些步骤?答:第一步_________________________________________________________ 第二步_________________________________________________________第三步_________________________________________________________预习新知除了直接证明的方法,还有_________证明的方法,_________法就是常用的间接证明方法.在证明一个命题时,有时先假设命题的________不正确,然后从这个___________出发,经过逐步_______________,最后推出与___________、__________、____________相矛盾的结果,从而得出________是错误的,__________正确的.这种证明命题的方法叫做反证法.用反证法证明一个命题是真明题的一般步骤是:第一步_________________________________________________________第二步_________________________________________________________第三步_________________________________________________________自学自测1.写出下列各结论的反面:(1)a//b;(2)a≥0;(3)b是正数;(4)有且只有一个交点;(5)一个三角形中最多有一个直角; (6)a ,b 中至少有一个等于0.2.求证:在同一平面内,如果一条直线和两条平行直线中的一条相交,那么和另一条也相交. 已知:如图,a ∥b ,c 与a 相交于点P 求证: c 与b 相交四、我的疑惑_____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________要点探究探究点:用反证法证明有关命题例1.试证明命题“三角形中最多有一个角是直角”.【归纳总结】若结论的反面不止一种情况,必须把各种可能情况全部列举出来,并逐一加以否定,才能肯定原结论是正确的. 【针对训练】试证明:在一个三角形中,至少有一个内角小于或等于60°.已知: . 求证: .证明:假设 ,则 .合作探究a bcP21H F G EDC B A ∴ . 即 .这与 矛盾.假设不成立. ∴ .例2.试证明:如果两条直线都与第三条直线平行,那么这两条直线也平行.已知: . 求证: .证明:假设 ,则可设它们相交于点A.那么过点A 就有 条直线与直线c 平行,这与“过直线外一点 ”矛盾. ∴假设不成立.∴ .【归纳总结】在推理论证时,要把新增的已知条件(即假设的内容)加进去,然后逐步推出与已知公理或定理之间的矛盾. 【针对训练】用反证法证明平行线的性质定理一: . 已知:如图,直线AB ∥CD ,直线EF 分别与直线AB 、CD 交于点G 、H ,∠1和∠2是同位角. 求证:∠1=∠2.例3.如图,在△ABC 中,AB=AC ,P 是△ABC 内的一点,且∠APB >∠APC ,求证:PB <PC (反证法)【归纳总结】反证法主要用于直接证明比较困难的命题.如结论以否定形式出现的命题,唯一性命题,结论含有“至少”“至多”等词.【针对训练】如图,在△ABC中,AB>AC,AD是内角平分线,AM是BC边上的中线,求证:点M不与点D 重合二、课堂小结反证法的意义反证法反证法的一般步骤用反证法证明有关命题当堂检测1.用反证法证明“在一个三角形中,至少有一个内角大于或等于60°”时第一步应先假设()A.每一个内角都小于60°B.至多有一个内角小于60°C.每一个内角大于或等于60°D.至多有一个内角小于或等于60°2.在证明“在△ABC中至少有一个角是直角和钝角”时,第一步应假设()A.三角形至少有一个角是直角或钝角B.三角形中至少有两个直角或钝角C.三角形中没有直角或钝角D.三角形中三个角都是直角或钝角3.反证法证明命题“同旁内角不互补的两条直线不平行”时,应先假设 .4.已知直线m、n是相交线,且直线l1⊥m,直线l2⊥n.求证:直线l1与l2必相交.5.已知a2=5,证明:a是无理数.6.如图,在△ABC中,D、E分别是AC、AB上的中点,且BD≠CE,求证:AB≠AC直角三角形全等的判定学习目标:1.理解直角三角形全等的判定方法“HL”,会用“HL”判定两个直角三角形全等.2.理解角平分线性质定理的逆定理.学习重点:理解直角三角形全等的判定方法“HL”.学习难点:“HL”的应用.自主学习知识链接1.勾股定理:如果直角三角形的两条直角边长分别为a,b,斜边长为c,那么2c=(或c=)变形:2a=(或a=),2b=(或b=)2.判定两个三角形全等的方法有:、、、二、新知预习1.动手试一试已知:两条线段(两条线段长度不相等),一条为2cm,一条为3cm.试着画出一个直角三角形,使3cm长的线段为三角形的斜边,2cm长的线段为其一条直角边.作法:(1)作一条线段CB,使它等于2cm;(2)过点C,作直线MC⊥CB;(3)以点B为圆心,3cm长为半径画圆弧,交射线CM于点A;(4)连接AB.△ABC即为所求2.将你画的三角形和同桌画的三角形进行比较,由此你能猜想到什么呢? 【结论】由上面的画图实验可以得到直角三角形全等的判定定理: 斜边和一直角边对应相等的两个直角三角形 (可以简写成“ ”或“ ”)3. 尝试证明以上结论 已知:如图,在Rt △ABC 和Rt '''A B C ∆中, ∠C=∠C’=90°,AB=A’B’,AC=A’C’ 求证:Rt △ABC ≌Rt '''A B C ∆ 【提示】先利用勾股定理证明另一条直角边相等,再用“SAS ”或“SSS ”证明这两个三角形全等 证明:自学自测 1.判断题:(1)一个锐角和这个锐角的对边对应相等的两个直角三角形全等( ) (2)一个锐角和锐角相邻的一直角边对应相等的两个直角三角形全等( ) (3)一个锐角与一斜边对应相等的两个直角三角形全等( ) (4)两直角边对应相等的两个直角三角形全等( ) (5)两边对应相等的两个直角三角形全等( ) (6)两锐角对应相等的两个直角三角形全等( )(7)一个锐角与一边对应相等的两个直角三角形全等( )(8)一直角边和斜边上的高对应相等的两个直角三角形全等( ) 2.如图,若要用“HL”证明Rt△ABC≌Rt△ABD,则还需补充条件( ) A .∠BAC=∠BAD B .AC=AD 或BC=BDC .AC=AD 且BC=BDD .以上都不正确四、我的疑惑_____________________________________________________________________________ _____________________________________________________________________________AB C A ’B ’C ’_____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________要点探究探究点:利用“HL ”判定两个直角三角形全等例1.如图,B 、E 、F 、C 在同一直线上,AF ⊥BC 于F ,DE ⊥BC 于E , AB=DC ,BE=CF ,你认为AB 平行于CD 吗?说说你的理由 解:AB 平行于CD理由:∵ AF ⊥BC ,DE ⊥BC (已知)∴ ∠AFB=∠DEC= °(垂直的定义) ∵BE=CF ,∴BF=CE在Rt △ 和Rt △ 中 ∵⎩⎨⎧==_______________________________∴ ≌( )∴ = ( ) ∴ (内错角相等,两直线平行) 【归纳总结】用“HL ”判定两个直角三角形全等时,要找到一组斜边和一组直角边对应相等. 【针对训练】求证:有一条直角边及斜边上的高对应相等的两个直角三角形全等.例2.请写出角平分线的性质定理的逆命题,并判断该命题的真假.【归纳总结】通过做辅助线构造两个全等的直角三角形,也是证明线段相等的常用方法. 【针对训练】如图:AB=AD ,∠ABC=∠ADC=90°,EF 过点C ,BE ⊥EF 于E ,DF ⊥EF 于F ,BE=DF .合作探究求证:Rt△BCE≌Rt △DCF二、课堂小结内容直角三角形全等的判定定理和对应相等的两个直角三角形全等.(可以简写成“”或“”)角平分线性质定理的逆定理定理到距离相等的点在这个角的平分线上.1.判断两个直角三角形全等的方法不正确的有()A.两条直角边对应相等 B.斜边和一锐角对应相等C.斜边和一条直角边对应相等 D.两个锐角对应相等2.如图,∠A=∠D=90°,再添加一个条件,即可使Rt△ABC≌Rt△DCB,理由是.3.如图,∠B=∠D=90°,BC=DC,∠1=40°,则∠2= .4.如图所示,已知在△ABC中,∠C=90°,AD=AC,DE⊥AB交BC于点E,若∠B=28°,则∠AEC=()A.28°B.59°C.60 D.62°5.如图,有两个长度相同的滑梯,左边滑梯的高度AC与右边滑梯水平方向的长度DF相等,两个滑梯的倾斜角∠ABC和∠DFE的大小有什么关系?当堂检测6.如图,公路上A、B两站相距25km,在公路AB附近有C、D两学校,DA⊥AB 于点A ,CB ⊥AB于点B.已知DA=15km,CB=10km,现要在公路上建设一个青少年活动中心E,要使得C、D两学校到E的距离相等,则E应建在距A多远处?勾股定理第2课时勾股定理的应用学习目标:1.能熟练运用勾股定理计算.2.会用勾股定理解决简单的实际问题.学习重点:用勾股定理解决实际问题.学习难点:勾股定理的熟练运用.自主学习知识链接1. 勾股定理:如果直角三角形的两条直角边长分别为a,b,斜边长为c,那么2c=(或c=)变形:2a=(或a=),2b=(或b=)2.填空题:在Rt△ABC,∠C=90°,⑴如果a=7,c=25,则b= ;⑵如果∠A=30°,a=4,则b= ;⑶如果∠A=45°,a=3,则c= ;(4)如果b=8,a:c=3:5,则c= .二、新知预习如图,一个3m长的梯子AB,斜靠在一竖直的墙AO上,这时AO的距离为2.5 m,如果梯子的顶端A沿墙下滑0.5m,那么梯子底端B也外移0.5 m吗?提示:梯子底端B随着梯子顶端A沿墙下滑而外移到D,那么的长度就是梯子外移的距离.②BD=-,求BD,关键是要求出和的长.③梯子在下滑的过程中,梯子的长度变了吗?④在Rt△AOB中,已知和,如何求OB?在Rt△COD中,已知和,如何求OD?自学自测1.小军量得家里新购置的彩电荧光屏的长为58厘米,宽为46厘米,则这台电视机的尺寸是(实际测量的误差可不计)()A.9英寸(23厘米)B.21英寸(54厘米)C.29英寸(74厘米)D.34英寸(87厘米)2.如图所示:是一段楼梯,高BC是3m,斜边AC是5m,如果在楼梯上铺地毯,那么至少需要地毯m.四、我的疑惑_____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________合作探究要点探究探究点:勾股定理的实际应用例1.如图,有两棵树,一棵高10米,另一棵高4米,两树相距8米,一只小鸟从一棵树的树梢飞到另一棵树的树梢,问小鸟至少飞行多少米?【归纳总结】解题关键是利用转化思想将实际问题转化成直角三角形模型,然后利用勾股定理求出未知的边长.【针对训练】如图,一根12米高的电线杆两侧各用15米的铁丝固定,两个固定点AB之间的距离是()A.13 B.9 C.18 D.10例2.一个门框的尺寸如图所示,一块长3m,宽2.2m的薄木板能否从门框内通过?为什么? 思考:①薄木板怎样好通过?;②在长方形ABCD中,是斜着能通过的最大长度;③薄模板能否通过,关键是比较与的大小.解:在Rt△ABC中,根据勾股定理AC2=()2+()2=2+2=.因此AC=≈.因为AC(填“>”、“<”、或“=”)木板的宽2.2m,所以木板从门框内通过.(填“能”或“不能”)【归纳总结】根据门框的尺寸,可以求出能通过此门框的薄木板的最大宽度,然后与之作比较【针对训练】小东拿着一根长竹竿进一个宽3米的城门,他先横着拿进不去,又竖起来拿,结果竿比城门高1米,当他把竿斜着时,两端正好顶着城门的对角,问竿长几米?二、课堂小结利用勾股定理求长度勾股定理的应用利用勾股定理解决实际问题当堂检测1.现有两根木棒的长度分别是40cm和50cm,若要钉成一个直角三角形框架,那么可以选用的木棒是()A.30cm B.40cm C.50cm D.60cm2.如图,在5×5的正方形网格中,下列数据与线段AB长最接近的是()A.4 B.5 C.6 D.73.小明用火柴棒摆直角三角形,已知他摆两条直角边分别用了6根和8根火柴棒,他摆完这个直角三角形共用火柴棒()A.20根B.14根C.24根D.30根4.一架2.5m长的梯子斜靠在一竖直的墙上,这时梯脚距离墙角0.7米,如果梯子的顶端沿墙下滑0.4米,那么梯脚移动的距离是()A.0.4m B.0.9m C.0.8m D.1.8m5.如图,能否将一根70㎝长的细木棒放入长、宽、高分别为40cm、30cm、50cm的长方体盒子中?勾股定理第1课时 勾股定理 学习目标:1.掌握勾股定理,能用拼图的方法验证勾股定理.2.会用勾股定理解决简单的问题. 学习重点:勾股定理.学习难点:勾股定理的验证.知识链接如果一个正方形的边长是a ,那么它的面积是 .2.如果一个直角三角形的两直角边分别为a ,b ,那么它的面积是 . 新知预习1.下图是用大小相同的两种颜色的正方形瓷砖铺成的地面.(1)图(1)中用白色框标出的三个正方形,他们的面积之间具有怎样的等量关系?(2)根据图(2),你能说出正方形面积之间的等量关系反映了Rt ∆ABC 三边之间怎样的关系吗?把它写出来.(3)如图(3),∆ABC 是直角三角形,∠ACB=90°.如果每个小方格子都是边长为1的正方形,那么Rt ∆ABC 的三边AC,BC,AB 的长各是多少?以AC,BC,AB 为边的三个正方形的面积各是多少?这些面积之间具有怎样的等量关系?对于更一般的情形,如果这个直角三角形的三边长分别是a ,b ,c ,那么可以怎样用a ,b ,c 把图中三个正方形面积之间的关系表示出来呢?自主学习图(1)A BC图(2) ACB acb 图(3)本实验的结论如何用文字语言加以叙述?4.如图是用四个全等的直角三角形拼成的,请根据此图验证你所得到的结论. 【提示】:用两种方法表示出大正方形的面积.【归纳总结】勾股定理:如果直角三角形的两条直角边长分别为a ,b ,斜边长为c ,那么 . 自学自测1.图中已知数据表示面积,求表示面积的未知数1s、2s 的值.2.图中已知数据表示边长,求表示边长的未知数1x 、2x 的值.四、我的疑惑_____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________要点探究探究点1:勾股定理的验证例1.比较图中两个正方形的面积,并验证勾股定理.【归纳总结】利用面积验证勾股定理,即从两个不同角度看一个图形的面积,建立含直角三角形三边的等式得到a 2+b 2=c 2. 【针对训练】如图是由三个直角三角形组成的直角梯形,请证明a 2+b 2=c 2.探究点2:利用勾股定理求值例2.如图,已知在Rt △ABC 中,∠C =90, (1)若5,12,a b 则c === ; (2)若10,8,c b a 则=== ; (3)若25,24,c a b ===则 . (4)若35a :=:c ,2b =a =则 ,c = .【归纳总结】由勾股定理的基本关系式a 2+b 2=c 2,还可以得到一些变形式.如:222222,a c b b c a c a b =-=-=+,.【针对训练】若直角三角形的两边长分别为3cm 、4cm ,则第三边长为 .二、课堂小结合作探究b c a c ABDC勾股定理的推导及验证勾股定理利用勾股定理求值1.若一个直角三角形的三边长为8,15,x ,则x = . 2.如图,学校有一块长方形花圃,有极少数人为了避开拐角 走“捷径”,在花圃内走出了一条“路”.他们仅仅少走了 步路(假设2步为1m ),却踩伤了花草.3.如图,分别以Rt △ABC 的三边为直径作半圆,其面积分别为1S 、2S 、3S ,且15S =,212S =,则3S = .直线同侧有三个正方形a 、b 、c ,若a 、c 的 面积分别为5和12,则b 的面积为 .5.已知:如图,等边△ABC 的边长是6cm. ⑴求等边△ABC 的高. ⑵求S △ABC .勾股定理第3课时 勾股定理的逆定理及其应用 学习目标:1.掌握勾股定理的逆定理.2.会利用勾股定理的逆定理判断直角三角形及解决实际问题. 学习重点:勾股定理的逆定理.学习难点:勾股定理的逆定理的应用.当堂检测知识链接1. 勾股定理:如果直角三角形的两条直角边长分别为a ,b ,斜边长为c ,那么 .文字叙述: 2.写出下列命题的逆命题:(1)同位角相等,两直线平行.它的逆命题是: (2)如果天空在下雨,那么地面是湿的.它的逆命题是: (3)对顶角相等.它的逆命题是: 新知预习1.画图:画出边长分别是下列各组数的三角形(单位:厘米) A.3、4、3 ; B.3、4、5; C.3、4、6;D.6、8、102.测量:用你的量角器分别测量一下上述各三角形的最大角的度数,并记录如下: A._______ B._______ C.______ D.______3.判断:请判断一下上述你所画的三角形的形状. A.______ B._______ C.______ D.______4.找规律:根据上述每个三角形所给的各组边长请你找出最长边的平方与其他两边的平方和之间的关系. A.______ B._______ C.______ D.______猜想:一个三角形各边长数量应满足怎样的关系时,这个三角形才可能是直角三角形呢?(1)结论:如果一个三角形的三条边长a 、b 、c 满足 ,那么这个三角形是直角三角形. (2)由于以上结论是勾股定理的 命题,所以我们把这个结论叫做 . 自学自测1.判断由a 、b 、c 组成的三角形是否是直角三角形:(1)a =15,b =8,c =17 (2)a =13,b =14,c =15 (3)a =41,b =4,c =5 (4)a =45,b =1,c =43(5)a =0.5,b =1.2,c =1.3 (6) a =21,b =23,c =222.若一个三角形的三边之比为5∶12∶13,且周长为60cm ,则它的面积为 .四、我的疑惑_____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________ _____________________________________________________________________________要点探究探究点1:勾股定理的逆定理的证明 问题:试证明勾股定理的逆定理.【提示】 构造一个与该三角形全等的直角三角形.已知:如图,在△ABC 中,AB=a ,BC=b ,CA=c ,且______________. 求证:∠C=90°.证明: 作△A’B’C’,使A ’B ’=a ,B ’C ’=b ,∠____=_____°. 由勾股定理,可得_____________________________________________ _____________________________________________ ____________________________________________ ___________________________________________ ___________________________________________ ___________________________________________ ∴△ABC ≌△A’B’C’( _______ ) ∴∠____=∠_____=90°.探究点2:利用勾股定理的逆定理判断直角三角形例1.已知a ,b ,c 为△ABC 的三边,满足442222b ac b c a -=- ,试判断△ABC 的形状.合作探究【归纳总结】对已知条件进行等式变形,化简,看是否能得到222c b a =+ 【针对训练】已知ABC Δ的三边分别a ,b ,c ,其中a =22n m -,b =2mn ,c =22n m +(m>n ,m ,n 是正整数),ABC Δ是直角三角形吗?说明理由.例2.如图,∠C =90°,AC =3,BC =4,AD =12,BD =13,试判断△ABD 的形状,并说 明理由.【归纳总结】先求出该三角形的三边长,然后验证这三边是否满足勾股定理的逆定理. 【针对训练】如图,在正方形ABCD 中,F 为DC 的中点,E 为BC 上一点,且EC=14BC ,求证:AF ⊥EF .【提示】 要证AF ⊥EF ,只需证△AEF 是直角三角形.不防设正方形的边长为1(或x ),然后利用勾股定理分别求出AE ,EF ,AF 的长,最后进行验证.探究点3:勾股定理的逆定理的实际应用例3.“远航”号、“海天”号轮船同时离开港口,各自沿一固定方向航行,“远航”号每小时航行16海里,“海天”号每小时航行12海里。
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Unit 4 My NeighborhoodLesson 21 Eat a Donut and Turn Right【Learning Aims】I Master the words:` downtown, coffee, through, cherry, sidewalk, himself, entrance.II Language points:lose one’s way, see a movie, write out, a piece of, some\two pieces of…, the way to, must be, say to oneself.【Foundation】I Free-talk: Have you ever lost your way?What do you do if someone asks you for direction?Key Words:__________________________________II words and phrases, then read.1 downtown _____________2 coffee _____________3 through _____________4 cherry _____________5 sidewalk _____________6 himself _____________7 entrance _____________ 8 lose one’s way _________9 see a movie _____________ 10 write out __________11 a piece of, some\two pieces of…, ________ 12 the way to __________13 must be __________ 14 say to oneself ___________III Sentences (Translation)1 Danny wrote out the directions for Brian on a pieceof paper because Brian doesn’t know the way to themovie theatre. ._________________________________________2 Brian says as he reads the paper. __________________.3 Can you tell me the way to the movie theatre?__________________?4 Turn right at the second crossing. _____________________________【Direction】I. Listening.Try to finish Part1 on Page 55II Read the lesson and write true(T) and false(F) On Page55III Talk about what you don’t understand in groups (vocabulary and senesces).IV finish part3 on Page55.【Self-check】根据汉语提示或首字母完成句子。
1 Mike learns French by h ____ because no one can understand French.2 I am l____. Can you tell me the way to the hospital?3 The travelers walked t_____ the forest (森林) and came back home.II Multiple choice.1 I need ____.A five piece of paperB five piece of papersC five pieces of papersD five pieces of paper2 Would you like to show me the way ____bank?—Sure.A onB forC withD to3 Suzan has bought a large house with a swimming pool.—It ____be very expensive. I never dream about it.A mustB mightC can’tD shouldn’t 【Consolidation】I Read in roles, then make their own dialogue about pointing directions. 【Expansion】Make a survey. Who is polite when he\she tells the Way to…______________________________________________________________ 【Assignment】1 Finish off the homework.2 Preview Lesson 22.3 Recite the words and the text.Unit 4 My NeighborhoodLesson 22 I need a Map (New Class)【Learning Aims】I Master the words: pond, freeze (froze, frozen), block, bank,whole, chat, cost.II Language points:play hockey, sometimes, chat with, at the grocerystore, in my neighborhood,cost/spend/ pay/take【Foundation】I Free-talk: What do you like to do after school? Where do you like to go?Do you do any housework? What do you do?Key Words:__________________________________II Words and Phrases, then read.1 pond _____________2 freeze (froze, frozen) _____________3 block _____________4 bank _____________5 whole _____________6 chat _____________7 play hockey _____________ 8 in my neighborhood _____________9 chat with… _____________ 10 at the grocery store _______________11 cost/spend/pay/take___________ 12 in my neighborhood________________III Sentences (Translation)1 During the winter it freezes, and I can play hockey on it with my friend.____________________________________.2 It’s only three blocks from my house.__________________________.3 Then I walk or ride my bike to the coffee shop.______________________________.4 Sometimes I sit for the whole afternoon and do my homework.____________________________________5. Other times I just chat with my friends.____________________________________【Direction】I. Listening.Listening to the tape and fill in the mind map on Page 57.ⅡRead the lesson and write true(T) or false(F). On Page 57.ⅢTalk about what you don’t understand in groups (vocabulary and senesces).【Self-check】根据汉语提示或首字母完成句子。
1 There are many fish in the p____ in the park.2 People often put money in the b_____.3 The new bike c____ me 500 yuan.II Multiple choice.1 What does your brother do? —_______.A He is a studentB He does his homeworkC He is tallD He walks in the park2 The ___family like football.A allB wholeC bothD either3 Digital cameras are becoming very popular, though some still ___ too much.A payB spendC sellD cost 【Consolidation】I Finish part 3 on Page 57.ⅡWrite a short passage about your neighborhood.【Expansion】What things make you enjoy your neighborhood? Think about it and talk it with your partner. ____________________________________________【Assignment】1 Finish off the homework.2 Preview Lesson 23.3 Recite the words and the text.。