视频格式大小比较

第一篇：视频格式大小比较

视频格式大小比较？mp4 avi 3gp rmvb wmv mkv mpg vob mov flv按大小排序？

 楼上说的很正确, 还有一种比较方法, 就是同一个内容用这些格式来压缩, 然后比较大小, 在网络上常见的大小数序如下, 小到大

flv, 3gp, mp4, mov, mpg, wmv, rmvb, mkv, avi

解释一下, flv都是那些视频网站在用, 为了网络传输, 肯定用最小的大小

3gp是手机在用, 这个也肯定不会太大

mp4都是移动设备在用, ipod和一些手机和播放器, 大了装不下的mov是苹果电脑常用格式, 苹果向来以效率著称

mpg其实很大的, 之所以大家都觉得它小, 是因为它是早期格式, 那时候的电影清晰的不高, 所以mpg的大小也不大

wmv是微软的, 用这个格式压缩的人不多, 很多都是恶意添加许可证, 让你必须连接到某个网站

rmvb是最常见的格式, 当初是为网络传播设计的, 要求很小的大小就能有很高的清晰度, 虽然比不过上面那些, 不过性价比很高, 用的人很多

mkv是新兴的格式, 大小不太了解, 只是电驴上面那些人经常用这个格式压缩高清影片, 每个都1G多, 很少见到小的

avi通常是发布最原始的无压缩的电影时用的格式, 大小就是DVD的4.2G, 提供给别人压缩并添加字幕的 drganfly-二级 2009-11-11 02:24

 1.首先要明确 LZ列明的都是封装格式 不是编码格式 他们各自都可以封装特定的数种编码格式 只有编码格式决定文件的大小 封装格式只是将数据打包起来而已

例如: mp4 avi mkv flv mov都可以封装h264 严格来说就不存在可比性了

2.不过 这些封装格式大多数情况下封装的编码格式有普遍的特定性 按照同等画质的前提下 各自所需要的数据量 可以粗略的排列他们的大小

mpg > 3gp > vob > rmvb > mov > flv > avi = wmv > mp4 = mkv

再次提醒 这是在要达到同等画质的条件下的文件大小的比较！

3.按照网络上流传的格式 其常见的文件大小来排列的话:

vob > mkv = avi > rmvb > mov = mp4 > flv = 3gp 匿名 2009-11-11 10:05

第二篇：比较大小 教案

比较大小

一、教学目标

1、掌握100以内数的顺序，会比较100以内数的大小。

2、引导学生独立思考，初步学习对数量的估计，逐步建立数感，理解多一些、多得多、少一些、少得多的相对性，并能够用准确地语言进行表述。

3、培养学生的合作与交流的意识与能力。

4、激发学生的学习兴趣，发展思维能力。

二、教学重难点：

理解多一些、多得多、少一些、少得多的相对性，并能够用准确地语言进行表述。

三、教学重难点：

正确熟练地进行比较

四、教具准备；

例4放大图两幅、投影片。

五、教学过程：

（一）、复习。

1、读出下列各数。35 76 89 90 96 100

2、老师报数，学生在本子上写数。六十九 九十三 八十 三十 一百

3、口答。(1)一个两位数，高位上是5，低位上是9，这个数写作()。(2)一个数，百位上是l，十位、个位都是0，这个数写作()。

（二）、新授。

1、教学例5。

(1)出示小棒图。教师问：左边有多少根小棒?右边有多少根小棒? 根据学生回答，教师板书； 42 37 教师追问：“左右两边的小棒，哪边的多?(左边多)42和37两个数比较。哪个数大?”

学生回答，老师再做说明，42和37相比较，42大，37小，我们用“>”来表示它们的关系。(2)出示计数器图。(3)让学生观察后问：

“左边的计数器表示多少?右边的计数器表示多少?”学生回答后，老师板书：23 25．又问：“23和25这两个数相比较，哪个数大，哪个数小，应该怎样表示?”老师在○里填上“<”大家齐读式子两遍。另一幅图提问个别学生谁大于谁?把你的想法说给大家听一听。

3、做课本第42页“做一做”。

先让学生独立做题，教师巡视指导，对有困难学生可对照数目表，做完后集体订正。

4、投影出示例6．

教师：红球有几个?(58个)蓝球有几个?(15个)黄球有几个?(10个)大家一起从15数到58，数的过程体会到15到58要经过好多的数。

教师告诉学生，58比15多得多，象刚才的题目我们就可以说，红球比蓝球多得多。请一个同学从10数到15，从中感受到l0到15比较接近，我们就可以说15比10多一些，象刚才的题目，我们就可以说黄球比蓝球少一些

5、第43页“做一做”

根据题意每人用“多一些、少一些、多得多、少得多”说一句话。

（三）课堂小结

大家说说今天有什么收获？

六、教学板书

生活中哪些地方用到了“多一些、多得多、少一些、少得多”这样的词语？

第三篇：大小作文

2011

1、小作文：

Directions: Some international students are coming to your university.Write them an email in the name of the Students' Union to

1)extend your welcome and

2)provide some suggestions for their campus life here.You should write about 100 words on ANSWER SHEET2.Do not sign your own name at the end of the letter, Use “Li Ming” instead.Do not write the address.(10 points).Dear Friends, On behalf of the Students’ Union of Beijing Foreign Studies University, I would like to extend our heartfelt welcome to all of the overseas students from all over the world to study in our university.It is my great pleasure to propose several practical suggestions to you.In the first place, life in this prestigious university perhaps is not as satisfactory as what you expected.You may be tightly bound by continual classes, excessive homework and exams.In the second place, in spite of all these adversities, you will still enjoy your life in this esteemed institution.All types of extracurricular activities such as sports meets, speech contests, different social gatherings and dancing parties provide ample opportunities to make friends.All in all, although there are many things lacking, life in our campus is a worthwhile period in your whole lifetime.Wish you enjoy your life here!Yours sincerely, Li Ming 亲爱的朋友们：

谨代表北京外国语大学学生会，向来我校学习的世界各地的海外学生表达衷心的欢迎。

我很荣幸地向你们提出一些实用的建议。首先，这所著名学府的生活也许不像你们所期待的那么令人满意。你们可能会陷入无尽的课程、大量的作业和考试。其次，尽管有这些课业，你们仍将享受这所大学的生活。运动会、演讲比赛、联谊会和舞会等各种各样的课外活动提供大量交朋友的机会。

总之，尽管有很多不足，我们的校园生活仍将是你一生中一段美好的岁月。希望你享受这里的生活！

您真诚的，李明

2、大作文：

Directions: Write an essay of 160-200 words based on the following drawing.In your essay, you should 1)describe the drawing briefly.2)explain its intended meaning, and 3)give you comments.You should write neatly on ANSWER SHEET2.(20 points)参考范文

As is symbolically illustrated in the cartoon, two individuals respond to the same event in completely diverse ways.The person on the left airs his dissatisfaction and disappointment when a bottle is overturned, while the man on the right is hurry to raise it up, with a sweet smile on his face.We are informed that various folks take different attitudes toward the same scene.The aim of the portrayal is to illustrate that keeping optimistic is of utmost significance to both our society and our life.In the first place, as an extremely vital psychological quality, optimism brings us creative power to play, arouses our enthusiasm for work and helps us overcome difficulties.In other words, with pessimism, achievements can hardly be made.In the second place, keeping optimistic gives us light when we are in dark and encouragement when we are dismayed.It is optimism, rather than genius and extraordinary ability, that inspires us to cope with any arduous task.With optimism, the goal we intend can be reached, and so can the hard nut be cracked.In conclusion, keeping optimistic encourages people to learn wisdom, humanity and self-confidence, and is a crucial and unavoidable aspect of any individual’s development of character and competence.参考译文：

如图所示，两个人对同一件事情的反应截然相反。当瓶子倒下时，左边的人表达了不满和失望，然而右边的人却面带微笑，急着把它扶起来。我们得知不同的人对同一事物看法不同。

这幅漫画的目的是阐明保持乐观对于我们的社会和生活都至关重要。首先，作为一种极为重要的心理素质，乐观给我们的娱乐带来了创造力，点燃了我们对于工作的热情，帮助我们克服困难。换而言之，如果悲观，我们很难取得任何成绩。其次，在我们身处黑暗时，乐观带来光明；在我们沮丧灰心时，乐观赋予勇气。正是乐观，而非天才或卓越的才能，激励我们应对任何艰难险阻。拥有乐观，我们才能实现计划中的目标，并且克服困难。

总之，保持乐观可以鼓励人们去学会获得智慧、博爱和自信，因此是个人性格和能力的培养过程中不可缺少的重要组成部分。2011 Part A: 小作文

Directions:

Write a letter to a friend of yours to

1)recommend one of your favorite movies and

2)give reasons for your recommendation.You should write about 100 words on ANSWER SHEET 2.Do not sign your own name at the end of the letter.Use”Li Ming”instead.Do not write the address.(10 points)Dear Bob, As one of your closest friend, I'm writing the letter in purpose of recommending one of my favorite movies to you, Around the World in Eighty Days.The primary factors for my recommendation as as follows.For one thing, this is a movie of science fiction which tells us an exciting story about an English gentleman,Mr.Phileas Fogg, who makes a bet with his clubmates and managers to travel around the world in eighty days.For another, it gives us a vivid description of the many difficulties and incidents which happen on his journey.Wish you enjoy the movie.Looking forward to your reply.(104 words)Yours sincerely, Li Ming

参考译文

鲍勃：

作为你最好的一位朋友，我写这封信是为了向你推荐我最喜欢的电影之一：《八十天环游地球》。

我推荐的主要原因如下。首先，这是一部科幻电影，讲述了一位英国绅士的一个激动人心的故事。菲力·弗格先生跟他的俱乐部伙伴打了个赌，并设法在八十天之内环游了地球。其次，电影生动描述了他在旅途中遇到的困难和发生的故事。

希望你喜欢这部电影。期待着你的回信。

你真诚的，李明

Part B: 大作文 Direction: Write an essay of 160-200 words based on the following drawing.In your essay ,you should 1)describe the drawing briefly, 2)explain its intended measing, and 3)give your comments.You should write neatly on ANSWER SHEET 2.(20 points)As is subtly portrayed in the cartoon, two tourists are taking sightseeing on a small boat while discarding their picnicing leftovers casually into a lake.Unfortuantely, the lake is already littered and teamed with flowing rubbish like plastic containers, fish-bones, banana skin, watermelon rind, bottles, tins, food wrappings, and so on.And below the drawing, there is a topic which says: “after” the travel or “me” in the travel.From the portrayal, we can conclude that the painter wants to convey such a message: a good many popular places are flooded with visitors, who spoil the beauty of nature by creating and leaving behind God-knows-how-much trash.On the one hand, tourism, as a multibillion-dollar business, is booming everywhere.Some people, laboring under the belief that tourism serves as an engine of economic growth, seem to ignore its negative effects on the environment.Nevertheless, it is my view that these are not concerns that we can shrug off lightly.On the other hand, tourism has exerted great pressure on the environment we are living in: water is polluted, the ecological system is disturbed, and natural resources have been excessively used.Undoubtedly, tourism could not be banned in any country as it does help to shore up the economy in places which offer few sources of income.The significant point is that the unchecked growth of the travel business may render the development of an economy unsustainable.It is high time that we enhanced people's awareness to rectify this by taking the environmental protection into consideration.(255 words)参考译文

如图所示，两名游客正在一艘小船上观光，同时把野餐的剩余垃圾随意丢入湖中。不幸的是，湖中已经堆满了漂浮的塑料盒、鱼骨、香蕉皮、西瓜皮、瓶子、罐头、食品包装等各色垃圾。在图画下方，有个小标题写明：“旅程之‘余’”。从漫画中，我们可以得出结论：画家想要表达下述信息：成群的游客涌入很多景点，通过生产并丢弃大量的垃圾从而破坏了大自然的美观。一方面，旅游业作为一项数十亿美元的产业，正在世界各地迅猛发展。有些人认为旅游业是经济发展的引擎，似乎忽视了其对环境的负面影响。然而，我认为我们必须充分关注这一问题。另一方面，旅游业已经对我们生存的环境造成了巨大的压力。水受到污染，生态平衡遭到破坏，自然资源被过度开发。

毫无疑问，由于在其他收入很少的地区，旅游业确实有助于发展经济，因此任何国家都无法禁止旅游业。重要的是旅游业毫无节制的发展可能使得经济发展不可持续。通过考虑环境保护因素，我们早就该提高人们的意识来扭转这个现象了。

2010 Part B Directions:

Write an essay of 160-200 words based on the following drawing.In your essay, you should

1)describe the drawing briefly，2)explain its intended meaning, and then

3)give your comments.You should write neatly on ANSHWER SHEET 2.(20 points)文化“火锅”：既美味又营养

文字说明：佛、解构、人本、功夫、毕昇、儒、礼、后现代、老舍、莎士比亚、爱因斯坦、道、仁、天鹅湖、启蒙、京剧等

As is symbolically illustrated in the portrayal, there is a boiling hotpot containing various ingredients of multi-cultures.These pluralistic cultures can be categorized as celebrities home and abroad as Bi Sheng, Lao She, Shakespeare and Einstein, philosophical concepts as Buddhism, Taoism, Confucianism, benevolence, rite, humanism, enlightenment, post-modernism and deconstruction, as well as performing arts as Peking Opera, Kong fu and Swan Lake.We are informed that the culture “hotpot” is both delicious and nutritious.The purpose of the cartoonist is to show us that instead of being outdated and of little value in a rapidly modernizing world, cultural blending should be encouraged and maintained.On the one hand, mosaic cultures are part of the universal heritage of humanity and they are powerful means of bringing together diverse peoples and social groups.Consequently, cultural reintegration has become indispensable as a means of promoting further culture development and maintenance.On the other hand, for China, as for any other rapidly developing country, there is a danger that age-old customs and traditions may become lost in the shadows of modernization.If kung-fu, Peking Opera or swan lake ballet ever perished from the earth, it would be a tragedy of immeasurable proportions.In my view, multi-cultures can be kept alive by the people with the time to do so, and is extremely vital in ensuring a community’s future development and prosperity.As a consequence of successful commercialization efforts, unwavering government support and growing interest overseas, the future of cultural blending looks brighter and more secure than ever before.如图象征性所示，一只沸腾的火锅中拥有诸多多元文化元素。这些多元文化可分为毕昇、老舍、莎士比亚、爱因斯坦等国内外名人，佛、道、儒、仁、礼、启蒙、人本、后现代、解构等哲学概念，以及京剧、功夫、天鹅湖等表演艺术。文字说明显示：“文化‘火锅’，既美味又营养。”

画家的目的是告诉我们文化融合并未过时或失去价值，相反还应鼓励和保持。一方面，多元文化作为全体人类遗产的一部分，是将不同人群和社会群体融合的有力方式。因此，文化融合作为促进文化发展和保护的一种方式，已经不可或缺。另一方面，中国跟世界上其他快速发展的国家一样，年久的习俗和传统面临着消失在现代化阴影里的危险。如果京剧、功夫或天鹅湖从地球上消失，那将是不可估量的悲剧。

在我看来，如果人们能为多元文化花费时间的话，那么它就能得以保护。这对确保社会将来的繁荣和发展都至关重要。由于成功的商业努力、政府坚定不移的支持和不断增长的海外兴趣，多元文化的将来会比过去任何时候更明朗、更安全。Part A Directions:

You are supposed to write for the postgraduate association a notice to recruit volunteers for an international conference on globalization.The notice should include the basic qualification for applicants and the other information which you think is relevant.You should write about 100 words on ANSWER SHEET 2.Do not sign your own name at the end of the notice.Use “ postgraduate association ” instead.(10 points)

Volunteers Needed

January 9, 2010 To improve students’ability and enrich extracurricular activities, the Postgraduate’Association is recruiting volunteers for an international conference on globalization to be held on April 7, 2010 in Beijing.To begin with, applicants should have Chinese nationality, a strong professional spirit, cheerful personality and be aged under 35.In addition, candidates must have outstanding skills at English listening comprehension and the ability to speak Chinese and English fluently.Finally, students with relevant professional experience are preferred.Those postgraduates who are interested in taking part in it may sign up with the monitor of their classes before February 1, 2010.Everybody is welcome to join in it.Postgraduate Association 参考译文

招募志愿者

2010年1月9日

为提高同学们的能力并丰富课外活动，研究生会现招募2010年4月7日在北京举办的一次国际全球化会议的志愿者。首先，应聘者必须具有中国国籍、较强的职业精神、令人愉快的个性，年龄在35岁以下。其次，申请人需具有卓越的英文听力水平以及流利的中英文演讲能力。最后，具有相关职业经验的学生优先考虑。有兴趣参加的研究生请于2月1日之前在本班班长处报名。欢迎大家积极参加。

研究生会 2008 Part B: Directions: Write an essay of 160-200 words based on the following drawing.In your essay, you should 1)describe the drawing briefly, 2)explain its intended meaning, and then 3)give your comments.You should write neatly on Answer Sheet 2.（图略）

文字说明：“你一条腿，我一条腿；你我一起，走南闯北。”

As is symbolically illustrated in the cartoon, supporting each other with their powerful hands, two handicapped adolescents are continuing their new journey on the ground.Crutches left behind, they have successfully cracked the hard nut of lameness which might have confused the majority of the disabled.The caption indicates, “You have merely one leg and so do I.Helping each other, we can travel all around.”

Undoubtedly, we can deduce from the portrayal that the cartoonist is trying to attract our attention to the issue of cooperation.According to a survey conducted among a group of people who were in the same college class 10 years ago, those who are ready to give their cooperation to others all become rich or managers of all field, while not a single young man having difficulty in getting along with their classmates becomes an executive or boss.Why those who are excellent in team work tend to be managers or own their own enterprise in their later life? The answer seems self-evident.On the one hand, if you are competent in profession, but have difficulty in getting along with your colleagues and even your boss, you can hardly survive the corporation.On the other hand, your chances of success are much higher with wide circle of friends who are willing to cooperate with you to provide information and resources.It is my view that, first of all, we can frequently use the drawings to enlighten the juvenile to learn to cooperate successfully with each other.On the other hand, whatever difficulty or situation we are confronted with, those who have the spirit of cooperation and team work are nearer to success.Just as John Adams, the second U.S.president quoted from the ancient Greek Aesop’s Fables, “United we stand, divided we fall.”

2009 Directions: Write an essay of 160-200 words based on the following drawing.In your essay, you should 1)describe the drawing briefly, 2)explain its intended meaning, and then 3)give your comments.You should write neatly on Answer Sheet 2.As is symbolically illustrated in the portrayal, the Internet is a spider web of thousands of networks, linking schools, universities, businesses, government agencies, libraries and millions of individuals.Undoubtedly, the Internet exerts such a profound effect on our life that it revolutionizes the way of people’s living and thinking.The exaggerative and impressive cartoon has subtly revealed the duality of the relationship between man and Internet.On the one hand, something like information superhighways, the Internet can bring many conveniences into the school, home and office.With a basic computer and modem, any individual can call up information about almost anything from almost anywhere and anytime.But on the other hand, a great many people admit that they are too much addicted to Internet to maintain a regular and wholesome lifestyle.Such a waste of time inevitably leads to their failure in their life and work.Hence, it is necessary for us to use Internet in a reasonable way and restrain from overindulgence.For one thing, in addition to providing us many of the facilities and services we now must travel to obtain, with the Internet, the computer will even let us communicate directly with other homes and with information sources worldwide.For another, as nearly all activities could be conducted in the comfort of our homes, we could all become hermit-like, never feeling any need to leave the computer.Accordingly, the challenge of the Internet means we should consider how we can use it, so that it won’t control us.Part A: Directions: Restrictions on the use of plastic bags have not been so successful in some regions.“White Pollution”is still going on.Write a letter to the editor(s)of your newspaper to 1)give your opinions briefly, and 2)make two or three suggestions.You should write about 100 words.Do not sign your own name at the end of the letter.Use “Li Ming”instead.You do not need to write the address.Dear Editors, I have been reading your newspaper for many years with a great enthusiasm and interest.It is my view that limiting the use of disposable plastic bags is of utmost significance.To crack this hard nut, I would like to propose several practical recommendations as follows.First and foremost, it is imperative for us to ban the free use of disposable plastic bags.In addition, we should develop possible alternative forms to replace them, such as paper or clothing bags.Last but not least, plastic bags should be offered in a much higher price in department stores or supermarkets.I hope you will find the above proposals conducive and I would like to discuss this matter to further details.Your prompt attention to my suggestions would be highly appreciated.Yours sincerely, Li Ming

第四篇：《比较大小》教案

100以内数的大小比较

望珺乙

教学内容

人教版小学数学教材一年级下册第42页。教学目标

1．知识与技能：使学生学会比较100以内数的大小，并体会比较两数大小的方法。

2．过程与方法：培养学生观察、比较、提出问题和解决问题的能力。3．情感、态度与价值观：利用现实有趣的情境激发学生的求知欲、学习数学的兴趣。

重点难点

重点：掌握比较100以内数的大小的方法。难点：正确比较100以内数的大小。教具学具 教具准备：课件。学具准备：数字卡片。教学设计

一、创设情境，导入新课

1．谈话：小朋友们，森林王国这几天可热闹了，大家都争先恐后地要报名参加数学夏令营活动，想加入吗？

可名额有限，人数又太多，怎么办？于是，聪明的小猴提出：只要你能回答我的三道问题，闯过三关，就有机会去夏令营，谁愿意做勇敢的闯关者？

2.出示：

第一关：42里面有()个十和()个一。

从右边起，第一位是()位，第二位是()位，第三位是()位。9是()位数，100是()位数，23是()位数。指名学生回答。

第二关：填上适当的符号（＞或＜）o 10○7 15○18

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集体用手势表示后指名两人说说，你是怎样比较的。第三关：请数出37后面的5个数。同桌相互数数。

3．谈话：祝贺小朋友们，你们闯关成功了，现在就可以顺利参加夏令营了。

二、自主探索，灵活比较

1．出示课件（小松鼠和小兔正在海边拾贝壳，小松鼠拾了37个，小兔拾了42个）。

(1)谈话：瞧，小松鼠和小兔正在海边拾贝壳呢，你还看到了什么？ 看着这幅图你想知道什么？小松鼠和小兔比，谁拾得多呢？ 你会比较吗？(2)合作交流。

谈话：请把你的想法先说给小组同学听一听（小组内交流）。可能情况：

a．我用数数的方法，42在37的后面，所以42比37多。b．四十几个比三十几个多，所以42比37多。

c．42的十位上是4，37的十位上3，4大于3，所以42比37多。谁愿意把你的想法说给大家听一听（在班内充分交流）。(3)谈话。

在这道题里比较哪一个小动物拾的贝壳多就是比较37与42哪一个数大。你能用一个数学符号表示它们之间的大小关系吗？

教师板书：42 37 指定学生板演：＞

全班学生读一读算式：42＞37。(4)提问。

谁能起来再和大家说说你是怎样比较它们的大小。（多指名学生充分说一说）2．出示课件。

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(1)谈话：参加夏令营的小伙伴人人都想取得好成绩，想比比自己的能力，于是他们请来了珠算先生当裁判，出难题考考大家。你能写出计数器上表示的数并比较它们的大小吗？

学生自己填写。

交流时要求学生说出比较的方法。(2)指名学生板演：23<＼25 0 追问：这时候，你又是怎么比较的？ 多指名学生充分说说自己的比较的方法。(3)完成“做一做”的第1题。

谈话：再来挑战一次，比一比这次谁的能力更强。集体交流，说说你的比较方法是什么。

三、实际应用，形成内需 谈话：比一比谁的反应最快。

1．抢答游戏：填上“＞”或“＜”（“做一做”的第2题）。请你用相应的手势快速表示。交流，说说自己的比较方法。2．写数游戏。

(1)下面我们再来动动小手，写出三个个位上都是6的两位数。学生写好后教师提问：你写了哪三个数？谁最大？谁最小？ 你能把这三个数按一定的顺序排列吗？（这个学生在黑板上排，其余学生在座位上排）为什么这样排？（可以从小到大，也可以从大到小排）个位上是6的两位数有几个？（顺次说一说）

(2)写出三个十位上都是6的两位数，比一比哪个最大，哪个最小。让学生都独立完成后再相互交流。

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四、课堂总结

提问：通过参加这次数学夏令营活动，你学到了什么数学知识？（揭示板书课题：100以内数的大小）

学会了什么本领，能和小朋友说说你的体会吗？（学生说说自己的体会）板书设计

教学反思

100以内数的大小比较这节课，是在学习100以内数的认识和顺序以及20以内数的大小比较的基础上学习的。100以内数的大小比较是小学阶段整数大小比较的基础和重点。现对本节课，反思如下：

一、创设情境，让学生体会数学的趣味性和实用性

本节课对教材进行了合理的开发与整合，构建了几个大活动板块，添加了一些活动素材，如创设故事情节——“拾贝壳比赛”，使学习素材富有现实意义，更具趣味性和挑战性，不仅充分调动了学生学习的主动性和积极性，也丰富并促进了他们学习情趣的养成。

二、在学习知识的同时注意思想方法的渗透

本节课注重为学生创设一些开放的问题情境，如“你是怎样比较42与37的大小的？”，“你是怎样想的？”等，而且注重为学生提供开放的探索空间，让学生能充分地进行独立思考、探讨交流等，在这种开放的学习过程中，使学生能积极去探寻解决问题的策略，主动去交流自己解决问题时的思维过程，充分去感受比较策略的多样化，增强了学生的自主意识，逐步加深学生对数学学习的认识和理解。

三、尊重学生，兼顾学习活动的有效性和发展性

本节课充分尊重学生的生活经验，充分尊重学生的选择，使他们在借助计数器比较的过程中经历了数学化的过程，有效地进行了比较方法的优化；充分尊重学生的理解，使他们在学习活动中不断感受到比较的现实意义和价值，而且充分尊重学生，也使得学生在有效的学习活动中，知识体验和情感体验不断得以丰富和提升，真正促进了他们的持续发展。

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第五篇：识字《大小》

识字《大小》教学设计

广安市特殊教育学校

彭晓燕

教学目标：

1、2、学生能初步比较两个物品的大小，理解大小的含义。学生能认读生字“大、小”。

3、能在生活中认读大小，提高学生的生活识字能力。

4、培养学生观察能力，激发学生识字的兴趣。A生：（程科铭、左青龙、李凤林）能初步比较两个物品的大小

能认读生字“大小”，理解大小的含义。能在生活中认读大小，培养学生的识字能力。培养学生的观察能力，激发识字的兴趣。B生：（周尚慧、辛大润、邓雨）能初步比较两个物品的大小。

能看图认读生字“大小”，在老师设定的环境中理解大小的含义。能激发学生的识字兴趣，提高学生的识字能力。C生：（曾朝诚、周欣、康欣雨、向雨涵）能参与课堂活动 能跟读生字“大小”。

能在老师设定的环境中，理解大小的含义。教学重点：

能认读生字“大、小”，理解大小的含义。教学难点：

1、能认读生字“大、小”，理解大小的含义。

2、能在生活中认读大小，提高学生的生活识字能力。

教学准备:ppt、实物大小不用的两个苹果、生字卡、图片（大门、小门、大床、小床、大碗、小碗）教学过程

一、创设情境，激发兴趣

1、师：同学们看看今天哪个卡通人物来到了我们的课堂？ 生：熊大熊二

2、解决问题

师：熊大熊二遇到了一个难题，你们愿意帮助他们吗？（生：愿意）这里有两个苹果，熊大想吃大苹果？你能帮他找到这两个苹果中哪个是大苹果吗？熊二想吃小苹果，谁来帮帮他？找到哪个是小苹果？

注：PPT同时出示（大苹果）（小苹果）

3、熊大熊二想和同学们一起来学习认识“大小”，以后他们就可以自己解决这样的难题了。出示课题：识字《大小》

二、探究新知

1、认读生字“大小”

师：刚才同学们知道了，这是大苹果，那你们知道这个字怎么读吗？教师拿出大的生字卡让学生认读 教师范读，教生读（让学生举起自己字卡中的大字）,开小火车读

师：同学们和熊大熊二一起学习了大这个生字，知道了大苹果的大，小苹果的小呢？他又长什么样子呢？ 师：拿出“小”字卡，和学生一齐认读

教师范读，教生读（让学生举起自己手中字卡中的小字），开小火车读

2、通过看图比较认读

熊大熊二为了感谢同学们帮他们找到自己想要的苹果，还和小朋友们一起高兴的学习了认识大小两个字。他们想请小朋友们到他家去做客，你们想去吗？好那我们现在就出发。

来到熊大熊二的家，你们看到了什么？师：出示图片，请学生观察两扇门有什么不一样？

门（大门、小门），一齐看图说一说抽B、C生来指认图片，A生将自己手中对应的大小字卡贴在大门和小门的旁边。走进门，我们看到两张床，一齐看图说一说哪张是大床，哪张是小床？抽B、C生来指认图片，A生将自己手中对应的大小字卡贴在大床和小床旁边。

我们再看看厨房有什么？两个碗，哪个是大碗，哪个是小碗？抽B、C生来指认图片，A生将自己手中对应的大小字卡贴在大碗和小碗旁边。

三、拓展练习，回归生活

1、在生活中，找到我们今天学过的“大小”。

好了，小朋友们刚才参观了熊大熊二的家，现在熊大熊二带我们到他家附近去看看，你们还能找到“大、小”两个字吗？如果你们能找到一会熊大熊二会拿好吃的款待大家。

师：PPT出示图片，抽生来找到各种标牌，与实物上的大小两个字，带领其他同学读一读。

3、小朋友，用你们的火眼金金再去找找我们生活中还有哪些地方能见到大小两个字，把他告诉自己的爸爸妈妈。

四、总结

1、今天熊大熊二欢迎你们到他家来做客，给同学们带来了美味的食物，你们想吃吗？那你能找到这个食物上有我们今天学过的小字吗？师：分发食物，逐个指导学生找到法式小面包中的”小”字。

五、板书设计

识字《大小》