六年级数学下册教案(北师大版).doc

to keep the city safe were gone in the thirty second the earth moved. out at sea it was calm. no wind came up. yet from every direction-east,weast,north,andsouth,strong winds blew upon the unlucky city. man himself had to make ruins of the citys best buildings so that they would not be a danger to those in the streets. a list of buildings undesteryed was now only a few addresses. a list of the brave men and the women would fill a library. a list of all those killed will never be made. amazing as it may seem, wednesday night was a quiet night. there were no crowds. the policemen saidnothing; even their horses were quit. there were no shouts or people doing crazy things. in all those terrible hours i saw not one woman who cried, not one man who was excited. before the fires, through the night, thousands and thousands of people who had lost their homes left for safety. some were covered in blankets. sometimes whole families put everything they owned and could save into wagons. they helped one another climb the high hills around the city. never in all sanfrsncios histroy were her people so kind as on that terrible night.unit 5elias storymy name is elias. i am a poor worker in southafrica. the time when i first met nelson mandela was a very difficult period of my life. i was twelve years old. it was in 1952 and mandela was the black lawyer to whom i went for advice. he offered guidance to poor black people on their legal problems. he was generous with his time, for which i was grateful.i needed his help because i had very little education. i began school at six. the school where i studied for only two years was three kilometers away. i had to leave because my family could not continue to pay the school fees and the bus fare. i could not read or write well. after trying hard, i got a job in a gold mine. however, this was a time when one had to got to have a passbook to live in johannesburg. sadly i did not have it because i was not born there, and i worried about whether i would become out of work.the day when nelson mandela helped me was one of my happiest. he told me how to get the correct papers so i could stay in johannesburg. i became more hopeful about my future. i never forgot how kind mandela was. when he organized the anc youth league, i joined it as soon as i could. he said:“ the last thirty years have seen the greatest number of laws stopping our rights and progress,until today we have reached a stage where we have almost no rights at all.”it was the truth. black people could not vote or choose their leaders. they could not get the jobs they wanted. the parts of town in which they had to live were decided by white people. the places outside the towns where they were sent to live were the poorest parts of south africa. no one could grow food there,. in fact as nelson mandela said:“ we were put into a position in which we had either to accept we were less important, or fight the government. we chose to attack the laws. we first broke the law in a way which was peaceful; when this was not allowed only then did we decide to answer violence with violence.”as a matter of fact, i do not like violence but in 1963 i helped him blow up some government buildings. it was very dangerous because if i was caught i could be put in prison. but i was very happy to help because i knew it would help us achieve our dream of making black and white people equal.the rest of elias storyyou cannot imagine how the name of robben island made us afraid. it was a prison from which no one escaped. there i spent the hardest time of my life. but when i got there nelson mandela was also there and he helped me. mr mandela began a school for those of us who had little learning. we read books under our blankets and used anything we could find to make candles to see the words. i became a good student. i wanted to study for degree but i was not allowed to do that. later, mr mandela allowed the prison guards to join us. he said they should not be stopped from studying for their degrees. they were not cleverer than me, but they did pass their exams. so i knew i could get a degree too. that made me feel good about myself.when i finished the four years in prison, i went to find a job. since i was better educated, i got a job working in an office. however, the police found out and told my boss that i had been in prison for blowing up government buildings. so i lost my job. i did not work again for twenty years until mr mandela and the anc came to power in 1994. all that time my wife and children had to beg for food and help from relatives or friends. luckily mr mandela remembered me and gave me a job taking tourists around my old prison on robben island. i felt bad the first time i talked to a group. all the terror and fear of that time came back to me. i remembered the beatings and the cruelty of the guards and my friends who had died. i felt i would not be able to do it, but my family encouraged me. they said that the job and the pay from the new south africa government were my reward after working all my life for equal rights for the blacks. so now at 51 i am proud to show visitors over the prison, for i helped to make our people free in their own land.a follower of bill gatesi have been a friend of bill gates for a long time. i knew him when he was a student at harvard university. we were surprised when he left university to set up his own company” microsoft” and make his own software. but he was the clever one! he is very good at writing computer languages and almost all computers now use microsoft software. the program “word” is used from britain to china! of course he has made a lot of money and that makes people very jealous. they want to stop his success. even the government is against him and has tried to break his company into two parts. they say that he is unfair to other people who want to sell similar software. because hefits his new software free in every new computer, the government says he is stopping other companies from selling their programs. this is not fair. everyone should be able to do what they can to make their company bigger. bill gates has not only done what he can to stop other competitors. he is very rich, but he is generous. he has given millions of dollars to help the education and the health of many children around the world. you could not meet a better man than bill gates.a competitors of bill gatesbill gates has been very successful and become very rich. he is very generous but how has he got his money? he has down this by making sure that no one else will be able to compete with his software. his software is not the best but it is used most widely in the world. when he sees what is needed, he makes a program and produces it quicker than anybody else. that way he gets a large part of the software market. then he works on improving the software later. he tries hard to stop others making better software. in 1995 the government tried to make things fairer for people like me. the government wanted to make microsoft into two companies so that neither of them was so strong nor so rich. this meant that they could not stop somebody else making new software. i always wonder how he could get so rich so quickly. has he done it by fair means? or has he done it by being a computer bully?必修二unit 1in search of the amber roomfrederick william i, the king of prussia, could never have imagined that his greatest gift to the russian people would have such an amazing history. this gift was the amber room, which was given this name because several tons of amber were used to make it. the amber which was selected had a beautiful yellow-brown colour like honey. the design of the room was in the fancy style popular in those days. it was also a treasure decorated with gold and jewels, which took the countrys best artists about ten years to make.in fact, the room was not made to be a gift. it was designed for the palace of fredrick i. however, the next king of prussia, fredrick william i, to whom the amber room belonged, decided not to keep it. in 1716 he gave it to peter the great. in return, the czar sent him a troop of his best soldiers. so the amber room became part of the czars winter palace in st petersburg. about four metres long, the room served as a small reception hall for important vistors. later, catherine had the amber room moved to a palace outside st petersburg where she spent her summers. she told her artists to add more details to it. in 1770 the room was completed the way she wanted. almost six hundred candles lit the room, and its mirrors and pictures shone like gold. sadly, although the amber room was cnsidered one of the wonders of the world, it is now missing.in september 1941, the nazi army was near st petersburg. this was atime when the two countries were at war. before the nazis could get to the summer palace, the russians were able to remove some furnitures and small art objects from the amber room. however, some of the nazis secretly stole the room itself. in less than two days 100000 pieces were put inside twenty-seven wooden boxes. there is no doubt that the boxes were then put on a train for konigsberg, which was at a time a german city on the baltic sea. after that, what happened to the amber room remains a mystery.recently, the russians and germans have built a new amber room at the summer palace. by studying old photos of the former amber room, they have made the new one looke like the old one. in 2003 it was ready for the people of st petersburg when they celebrated the 300th bithday of their city.a fact of an opinionwhat is a六年级数学下册教案教学目标：1巩固加深对所学知识的理解，沟通各部分知识的内在联系，将所学的知识系统化。2应用所学的知识解决简单的问题，总结解决问题的策略，并尝试提出新问题。3回顾学习过程及解决问题的过程，逐步养成整理回顾和反思的习惯。4体会知识与生活之间的联系，增强应用数学的意识，体会数学的魅力。5与同伴交流学习过程中的收获与自己的不足，形成实事求是和敢于质疑的态度，发展自信心和克服困难的意志。 教材分析：教材将小学数学所学内容按课程标准划分为“数与代数”“空间与图形”“统计与概率”3个领域，同时，教材还设计了回顾解决问题策略的内容。每一部分内容的呈现又分为“回顾与交流”“巩固与应用”两个方面。每一部分的“回顾与交流”主要是对重点知识及学习方法的梳理；“巩固与应用”主要是通过练习和应用，一方面巩固所学的知识，澄清学习中的困难，另一方面提升学生分析问题、解决问题的能力。解决问题的策略主要是梳理学生在以前的学习过程中用到的解决问题的策略，如列表、画图、猜想与尝试、从特例开始寻找规律等。在小学阶段，为什么要设立这样一个总复习呢？它不只是做练习题，在练习中形成一定的技能，总复习主要目的有以下几个方面：一是加深学生对所学数学知识和方法的理解，在形成一定技能的同时，通过复习，突出核心概念及核心方法。基本技能要达到准确、熟练，除了必要的基础练习外，还要进行一些变式的、综合的练习。但应注意，基本技能应按照课程标准的要求，依据学生的认知规律进行有目的、有计划、有效的练习，不提倡进行机械训练，更不能让核心概念及核心方法湮灭于题海中。二是加强所学内容之间的联系。通过总复习，沟通知识之间的联系，有利于学生把学习迁移到新的情境。数学知识、方法之间有着密切联系，在实际教学时，教师要为学生提供自主梳理知识的时间和空间，不能越俎代庖。学生良好的认识结构是在个人思考中初步建立、在小组合作中形成、在班级交流和老师的指导下不断提升的。三是积累数学活动经验，体会数学思想。总复习除了需要对所学内容进行回顾、整理、巩固、应用外，还有一个重要目标，就是帮助学生再次经历重要概念和方法的形成过程，经历综合应用所学内容解决问题的过程，使他们不断积累活动经验，体会一些重要的数学思想。四培养学生的问题意识。在复习时，不仅应复习相应的知识和技能，还要把相应的知识与解决问题结合起来。这样，既可以帮助学生回忆、整理相关知识，同时可以帮助学生提高综合运用数学知识的能力。特别要注意的是，教师要引导学生提出新的研究问题，培养学生的问题意识。能提出有价值的问题，往往代表学生对所学内容有了比较深入的理解。五是促进学生良好学习习惯的养成。自觉整理知识，回顾、反思自己学习过程中的方法和策略，都是良好的学习习惯。基于以上的考虑，在教材的编写中，我们力求体现以下几个方面的主要特点：1重视沟通知识的内在联系教材在安排复习时，首先注重沟通知识的内在联系，把平时相对独立学习的知识以分类、归纳、转化等办法串起来，使相关内容条理化、结构化，形成整体框架，以加深学生对所学内容的理解。教材中设计了很多整理的内容，如学过的数的联系、数之间的相互转化、四则运算的意义及关系、估算策略的总结、计算法则和运算规律的总结等。2注重学习方法的渗透教材既关注数学内容的整理及其内容之间的联系，也关注在学生过程中渗透整理和反思的方法。教材通过设计问题和活动引导学生的复习方法，培养他们良好的学习习惯。教材结合有关问题引导学生进行知识归类，梳理知识之间的联系，并引导学生用表格或网络图等形式来呈现。教材还在多个地方对学生梳理知识的角度进行提示，如对运算规律的整理与验证方法的整理等。3注意整理与应用相结合教材注重整理与应用相结合，每部分内容的复习都分为“回顾与交流”“巩固与应用”两部分。“回顾与交流”以提示性问题的形式呈现，把主要知识内容加以呈现，以便于教师引导学生进行梳理，把以前分散学习的知识进行系统整理，沟通知识之间的联系。在“巩固与应用”部分，练习的设计既注意基本知识和基本技能，又注意知识的综合应用，引导学生综合运用学过的数学知识和方法解释生活中的现象、解决简单实际问题，增强解决问题的能力和反思意识。数的认识教学设计一、教材分析 总复习数的认识一课是义务教育课程标准实验教科书数学（新世纪版）六年级下册40页41页的内容。从本节课开始，我们进行复习小学六年所学习的内容，在学习内容的安排上教材注重为学生提供自主梳理知识的时间和空间，在个人反思、小组合作、班级交流和教师指导下不断提升学生的认知结构。在复习的过程中，不断积累复习活动的经验，引导学生逐步养成整理回顾和反思的习惯，增强数学的应用意识。 在教学中，教师要重视学生的情感体验，采用多种形式（如采用“小测试”活动、自主整理“知识树” 、采用形式多样的练习方式、开展丰富多彩的学习活动等）调动学生的学习积极性，另外教师还要特别重视学生的差异，对学习有困难的学生有针对性地进行辅导，在复习的过程中帮助他们解决学习上的困难，树立学好数学的自信心。 教材内容的数学核心思想数形结合的思想、极限的数学思想。在复习中，将抽象的数学语言与直观的图形结合起来，来解决数学问题，实现数形结合，使抽象思维与形象思维结合。而在本课中学生通过梳理知识树、用数轴来整理知识还是用表格来整理知识，都是数形结合思想的应用。在整理和复习中渗透极限的数学思想，本课示出：“整数、小数、分数、百分数”。分类后，教师追问：除了黑板上的这些数，你还能再写几个吗？在学生写的过程中，引导学生体会数的个数是无限的，体会极限的数学思想。 二、学生分析 我校是一所寄宿制学校，而现在的六年级学生大部分来自城市，极个别来自农村，学生基础相对均衡，学生在经过五年多的学习，已经能够根据学习内容尝试着去提出数学问题、分析问题并解决问题，能够比较有效地进行小组合作学习。这个年级的学生，经过近四年自主整理能力的培养，具有很强自主整理知识的能力，能够很快地整理出“知识树” 。 为了更好地把握教学设计的起点，课前我在我校六年级一班随机找了10个学生进行了调研。同时也抽取了8位学生进行了个别访谈。通过调研，看到本班“小测试”的正确率是10%的，学生仍然没有养成先审题，再下笔的习惯。对于知识的整理，学生个人需要6-8分钟的时间，能够把所学的知识进行一定的梳理，看来学生有一定的生活经验，但缺乏方法和系统。所以，我打算在课堂上采用小组分工合作的方式进行知识整理。 三、学习目标 知识与技能：在具体的情境中，回顾和整理小学阶段所学习的数，沟通各种数之间的关系，进一步弄清概念间的联系与区别，构建数的认识的知识网络；在学习的过程中体会数的扩充过程，进一步体会数在日常生活中的作用，会用数来表示事物并进行交流。 过程与方法：经历学习过程和解决问题的过程，发展学生的数感，逐步养成整理回顾和反思的习惯，增强数学的应用意识，体会数学的魅力。 情感、态度和价值观：在学习活动中形成解决问题的一些基本策略，获得成功的学习体验，树立学习数学的自信心。 四、教学过程 （一）热身测试，跌入陷阱。（5分钟） 六年的数学学习即将结束，同学们学习得怎么样？下面我们来做一个小测试。请同学们在2分的时间内完成，看哪些同学能圆满地完成。 （师提醒学生，等试卷全部分发完后，大家同时看试卷，然后答卷） 附：测试题目 1、请你认真地把试卷读完，然后请在试卷左上角写上自己的姓名。 2、一个五位数，加上1就成为了六位数，这个五位数是（ ）。 3、5千克煤发电12度，每度电需要（ ）千克煤，每千克煤能发电（ ）度。 4、按要求，填一填。 5、当a是（ ）时，分数a/9 是真分数，当a（ ）时，分数a/9 是假分数。 6、小明从家到学校要走1.5时，30分钟可以走全程的几分之几？（详细写出你的思考过程） 7、如果你已经认真读完了以上6道题目，只完成第1题。完成的同学请不要出声，静静地等待2分钟的到来，好吗？ 【设计意图：设计“小测试”活动，目的是引导学生学会反思，反思自己认真审题的习惯，给学生心灵带来深深的震撼，引导学生在体会中感悟，在感悟中反思，在反思中促进学生数学学习习惯的养成。】 教师提醒学生，时间已经过去一半了，快点儿，快点儿！ 时间到！现在我了解一下，谁按要求完成的请举手！（没人举手）啊？不会吧，怎么一个同学也没有做完？ 谁能说一说现在你有什么收获？ 【设计意图：在谈收获的活动中，加强学生的情感体验，让学生时时提醒自己认真审题，让学生内心深处有所触动，养成良好的学习习惯。】 小结：从“小测试”活动中我们再次感受到认真审题的重要性，希望在以后的数学学习中大家能够养成认真审题的好习惯。 （二）创设情境，自主整理。（17分钟） 刚才我们进行了一个测试，看来审清题目的确很重要，下面我们一起来看一幅图，比一比看谁最细心？ 这个图片熟悉吗？这个图片是我们五年级数学课本上的一幅图，请你认真再观察这幅图，图中有哪些数？你能把这些数分分类吗？ 【设计意图：创设情景引导学生找一找图中的数，在回顾的基础上进行分类，让学生在回顾中梳理知识。另外，在分类过程中，多样化的分类为知识整理进行了很好的铺垫，分类的过程也是教师引导学生深入学习的过程，通过师生对话使学生加深对所学知识的梳理。】 学生进行分类，从而揭示出：“整数、小数、分数、百分数”。分类后，教师追问：除了黑板上的这些数，你还能再写几个吗？ 【设计意图：在学生写的过程中，引导学生体会数的个数是无限的，体会极限的思想。】 回顾一下这些数有什么联系和区别，自己独立想一想，你会如何整理？在小组内交流自己的想法，老师给4分钟的时间，每个小组整理出一份你们满意的“知识树” 。 学生展示汇报。 调研时学生现场整理的“知识树” ： （5） 整 数 分 数 小 数 百分数 自然数 负 整 数 真 分 数 假 分 数 有限小数 无限小数 正 整 数 0 循环小数 教师根据学生的汇报相机强调： （1）最小的自然数是0，没有最大的自然数；最大的负整数是-1，没有最小的负整数。 （2）带分数是由整数和真分数合成的数。 【设计意图：学生是数学学习的主人，课堂上充分发挥学生的主体作用，自主整理，整体建构，在对话、交流、协商中构建自己的知识体系。】 （三）拓展阅读，加深理解。（4分钟）数的发展经历了一个漫长的过程，数起源于数（sh）。远古时代，人们在狩猎、捕鱼和采集果实的劳动中，数的概念开始萌生。 在我国河南省发现的殷墟甲骨文卜辞中有很多记数的文字，说明早在三千多年前人们已经能用一、二、三、四、十、百、千、万等记数，下面是甲骨文中的一些数： 我国最早使用的算筹。下面是算筹记数的两种形式： 经过了很长的时间，才产生了现在通用的阿拉伯数字。 1 2 3 4 5 6 7 8 9 0 以上是老师搜集到的一些关于整数的发展，课下请同学们也搜集一下关于分数、小数、负数发展的资料，进行交流，行吗？ 【设计意图：再次感受数的发展过程，感受数与现实生活的密切联系，总复习不仅是所学知识的简单回顾和整理，还需要了解一些数学的发展史，从整体上将学生的数学思想加以提升。】 请你认真阅读课本41的内容，说一说现在你有什么收获？（四）利用情境，巩固练习。（12分钟） 通过刚才的展示，我发现我们班的确是很棒的！现在请大家完成第2 6题，时间为2分钟。你认为哪个题目需要老师帮助？ 课下，我们针对这部分所学的内容，自己出了一些题目，谁能够象老师这样来考考大家？ 调研时学生所出的部分题目： 一、 填空。 1、桌子上有一堆糖，小红数了数，共22颗，可以用（ ）数表示糖数。 2、十五万九千零四十写作（ ），改写成用“万”做单位的数是（ ）。 3、最小的自然数是（ ），最小的合数是（ ），（ ）既不是质数，也不是合数。 4、小数点左边第五位是（ ）位，小数点右边第二位是（ ）位。 5、将下面的数从小到大排列。 3.2 3 5.88 0.58 0.589（ ）（ ）（ ）（ ）（ ） 二、判断。 1、负数都是整数。 （ ） 2、奇数+奇数+偶数=质数。 （ ） 3、负6摄氏度写作 -6摄氏度。 （ ） 4、整数分为正整数和负整数。 （ ） 【设计意图：作为教师要充分挖掘每个题目的价值，使每个题目得到充分的利用，另外，让学生展示自己出的题目来考大家，形式新颖，学生参与练习的积极性高，在寓教于乐的学习活动中促进学生的发展。】 （五）看书质疑，小结新知。（2分钟） 今天我们所学的内容在课本的40页、41页的内容，认真看一看。 通过这节课的学习，说一说你又有什么收获与体会？ 【设计意图：看书回顾，谈谈收获，从总体上对本节课进行回顾，使学生对所整理的内容再次整体建构，加深对所整理内容的理解。】 五、教师反思： 本节课，我考虑了很长的时间，一直在思考两个问题：（1）简单的课如何上得有深度、有厚度？（2）如何在课堂教学中使学生真正成为学习的主人？作为即将毕业的学生而言，回顾六年的数学学习是一个很重要的过程，我主要从以下几个方面进行设计的：首先通过“小测试”活动，引起学生内心深处的震撼，在活动中引导学生体验审题的重要性，这样的体验远比教师的说教好得多。本节课注重凸显学生的主体地位，在自主整理和自主出题环节充分得以展现，在课堂上学生现场分小组合作整理“知识树”是对学生六年来的知识整理能力和小组合作能力的一种检查和反馈。而整数数学史的介绍更让学生感受到数学的价值和魅力，使学生在学习数学知识的同时，情感得以升华。 “数的认识”一课上完了，但我的思考没有停止，“我们总习惯于在学生做练习时反复提醒：先审题，再下笔。然而，年复一年，日复一日地提醒得到的依然是学生的我行我素，拿题即做，结果仍然是屡说屡错，屡错屡说。”所以，我在课堂中引用特级教师华应龙老师的引入方式，在学生内心深处留下强烈的震撼。在教学中，我引导学生主动地复习，共同重温并整理所学的知识，使之系统化。在回忆和整理知识时，要让学生做复习的主人，多让学生发言，互相补充，逐步形成系统的、完整的、明确的知识网络。这样，学生对所学知识不仅加深了理解，印象深刻，而且感到通过复习和整理确实有所提高，从而激发学生复习的积极性，提高复习的效果。 数与代数教学目标：1、在具体情境中，回顾和整理小学阶段所学习的数，沟通各种数之间的关系，构建数的认识的知识网络。2、进一步理解自然数、小数、分数、负数的意义及表示方法，能进行小数、分数、百分数之间的转化。3、总结整数、小数、分数比较大小的方法，并进行比较。4、在解决实际问题的过程中体会数的扩充过程；进一步体会数在日常生活中的作用，会用数来表示事物并进行交流。教学重点和难点：建立知识网络，掌握复习数学方法，数学思想教学准备：幻灯片教学步骤：一、情境导入展示生活中常用的数，然后教师说：“既然数在数学世界里有着举足轻重的地位，在小学阶段，我们曾经学过哪些数？”学生随后回答：“自然数、整数、小数、百分数等。”师说：“你能用自己的方式把这些学过的数清楚地表示出来吗？”二、学生通过独立思考，构建自己对数的认识的知识网络。教材中提供了一幅网络图，是将数分成了整数和分数。这里有三点说明：第一，由于小学阶段负数只是初步学习，学生只要借助具体情境体会引入负数的必要性以及负数的意义即可；而正数与负数之间表示的是具有相反意义的量这一点，学生通过负整数的复习就能够理解。因此，在图中只出现了负整数，没有进一步出现负分数。第二，在小学阶段由于学生没有学习无理数（除外），所以分数和小数是一致的，因此在图中用分数进行表示。实际上，小数与实数是等价的、分数与有理数是等价的。为学生后续初中学习奠定基础。第三，为了复习需要，将数分成了整数和分数，实际上整数可以看成分母为1的分数。教学时，教师需要把握重点，这个活动的重点是帮助学生沟通各种数之间的联系，构建知识体系，因为在头脑中将知识形成一定的结构更有利于学生记忆和应用，教师不必把整数是否为分数等细节问题作为讨论的重点。（教学是要为学生提供充分交流的平台，可以让学生县独立思考，然后在小组内交流，最后在全班进行汇报。这是一个学生互相学习的最好契机，教师一定要精心准备，善于发现，引领学生更全面、更科学，更系统地回顾和掌握这部分内容。）接着，教师先鼓励学生在数轴上将所学的数表示出来。同时，借助数轴可以直观地将数进行大小比较，数轴为学习数提供了一个最为直观的模型，数学中应充分利用。（培养学生数形结合思想）三、呈现学生曾经经历的一些熟悉的生活情境，让学生谈自己的理解和感想。第一幅图，学生在用正整数表示苹果的个数，使学生认识到为了表示数量的多少，产生了正整数；第二幅图，提出了如何表示“没有”的问题，也就是0的产生；第三幅图，提出了如何表示“一个蛋糕平均分成4分后的其中一份”的问题，也就是需要引入分数；第四幅图，提出了如何表示 “零下2摄氏度”的问题，也就需要引入负数。在教学时，鼓励学生自己根据这些情境说出所学的数的发展过程，感受引入分数、负数的必要性；然后再让学生结合生活中的常见例子，举出一些来，说一说生活中这些书的应用。（这个活动的目的是使学生回顾引入新数的过程，体会现实生活的需要时数的扩充的一个重要原因，再次感受数的发展过程，感受数与现实世界的密切联系。这个活动也体现了总复习的作用，总复习不仅仅是对以前所学内容的简单回顾和整理，还需要从整体上重新将所学内容串起来，帮助学生在数学思想上加以提升。）四、总结教学时，教师可以指导学生自己进行整理，全班交流。整数（第1课时）教学目标：1、在具体情境中，能认、读、写亿以内的数，会用数表示物体的个数或事物的顺序和位置；了解十进制计数法，会用万、亿为单位表示大数。2、结合现实素材感受大数的意义，并能进行估计。了解负数，会用负数表示一些日常生活中的问题。3、回顾有关因数、倍数、质数、合数、奇数、偶数等概念，巩固求公因数、最大公因数、公倍数、最小公倍数的方法。4、逐步形成知识网络，掌握一定的数学方法、数学思想。教学重点和难点：结合具体情境理解意义是重点，掌握数学方法、体会数学思想是难点。教具准备：幻灯片 挂图教学过程：一、回顾与交流呈现学生熟悉、生动、有价值的数学信息。帮助学生对整数意义、表示、比较大小、实际应用等有个全面认识，使学生学到知识更加系统化，并能综合运用所学的内容。信息1帮助学生全面理解正整数的意义：基数、序数、测量结果、编码。教材呈现了生活中的一些信息，这些信息不仅体现了数的应用，也体现了正整数的不同意以。教材又进一步提出讨论的问题：“上面的信息中有哪些数，你知道他们的具体意义吗？”引导学生理解这些数的具体意义。对于正整数的意义，不要求学