四年级数学上册第一单元的知识点.docx

1、四年级数学上册第一单元的知识点XX四年级数学上册第一单元知识点第一单元【大数的认识】、一万一万地数，10个一万是十万；10个十万是一百万；10个一百万是一千万；10个一千万是一亿。2、一（个）、十、百、千、万亿都是计数单位。个位、十位、百位、千位、万位、十万位、百万位、千万位、亿位、十亿位、百亿位、千亿位是数位。位数是指一个数由几个数组成。四年级数学上册第一单元知识点-zpsxXX33-3、相邻两个计数单位之间的进率是十。4、我国的计数习惯，每四个数位是一级，可分为个级，万级，亿级三级。、多位数的读法：读数时，先分级，然后从高位到低位先读亿级，再读万级，最后读个级。在读到亿、万级的末尾时加上亿

2、和万字。每级末尾不管有几个0，都不读。其它位置的0要读，不过在一起的0只读一个0。6、多位数的写法：先把读出的数按级分成亿级、万级、个级三级，然后从高位到低位先写亿级，再写万级，最后写个级，没有读出来的数0补齐。7、为了读写方便，把整亿、整万地数改写成用“亿”、“万”做单位的数。如130000=13万（去掉个级四个0后添上单位万）1XX00000=12亿（去掉个级和万级八个0后添上单位亿）8、四舍五入法：求一个数的近似数，主要是看它省略的最高位上的数，是小于，大于还是等于。如果省略的尾数最高位上的数是4或比4小，把尾数都舍去。如果省略的尾数最高位上的数是或比大，把尾数省略后向前一位进一。9、关

3、于近似数的问题在实际问题中，有些数据是与实际完全符合的准确数。如：三班有12个男同学，27个女同学。这里的“12”“27”都是准确数。还有些数据，只是与实际大体符合的近似数。我们在测定物体的长度、质量时，由于测量工具的限制，必然会产生误差，所得的结果都是近似数。如：小明身高140厘米，体重3千克。这里的“140”、“3”都是近似数。在对大的数目在进行统计时，一般也只需要用它的近似数来表示。如：平常说一个城市有0人，一个钢铁厂去年产钢120万吨。这里的“0万”、“120万”都是近似数。0、古时人们是通过“实物”、“结绳”“刻道”等方法来记数的。1、表示物体个数的1234都是自然数。一个物体也没有

4、，用0表示。0也是自然数。2、最小的自然数是0，没有最大的自然数，自然数的个数是无限的。3、每相邻的两个计数单位之间的进率都是十，这种计数方法叫做十进制计数法。4、为了方便计算，人们发明了各种各样的计算工具。早在14世纪，中国就发明了算盘。现在比较常见的计算工具是电子计算器。要知道开关机、删除、运算符号键等。E为清除键，N/为开关及清屏键。赠送以下资料英语万能作文(模板型）Along with the advance of the society more and more problems are brought to our attention, one of which is that.

5、随着社会的不断发展，出现了越来越多的问题，其中之一便是_。As to whether it is a blessing or a curse, however, people take different attitudes.然而，对于此类问题，人们持不同的看法。(Hold different attitudes 持不同的看;Come up with different attitudes 有不同的看法)As society develops, people are attaching much importance to.随着社会的发展，人们开始关注.People are attaching

6、 more and more importance to the interview during job hunting求职的过程中，人们慢慢意识到面试的重要性。As to whether it is worthwhile ., there is a long-running controversial debate. It is quite natural that people from different backgrounds may have divergent attitudes towards it.关于是否值得_的问题，一直以来争论不休。当然，不同的人对此可能持不同的观点。I

7、n the process of modern urban development, we often find ourselves in a dilemma.在都市的发展中，我们往往会陷入困境。Recently the phenomenon has aroused wide concern, some people are in alarm that.最近，这种现象引起了人们的广泛关注，有人开始担心_。The human race has entered a completely new stage in its history, with the increasingly rapid ec

8、onomic globalization and urbanization, more problems are brought to our attention.人类进入了一个历史的崭新的阶段，经济全球化、都市化的速度不断加快，随之给我们带来了很多问题。. plays such an important role that it undeniably becomes the biggest concern of the present world, there comes a question, is it a blessing or a curse?_显得非常重要而成为当今世界所关注的最大

9、的问题，这是无可厚非的。不过，问题是：我们该如何抉择?Now we are entering a new era, full of opportunities and challenges,现在我们正在进入一个充满机会和挑战的新时代。People from different backgrounds would put different interpretations on the same case.不同行业的人对同一种问题的解释不尽相同。The controversial issue is often brought into public focus. People from diff

10、erent backgrounds hold different attitudes towards the issue.这中极具争议性的话题往往很受社会的关注。不同的人对此问题的看法也不尽相同。When asked ., some people think. while some prefer.说到_，有人认为_，而另一些人则认为_。Just as the saying goes: so many people, so many minds. It is quite understandable that views on this issue vary from person to per

11、son.俗话说，。不同的人对此有不同的看法是可以理解的。To this issue, different people come up with various attitudes.对于这个问题，不同的人持不同的观点。There is a good side and a bad side to everything, it goes without saying that.万事万物都有其两面性，所以，勿庸置疑，_。When it comes to ., most people believe that ., but other people regard .as .提到_问题，很多人认为_，不

12、过，一些人则认为_是_.When faced with., quite a few people claim that ., but other people think as.提到_问题，仅少数人认为_，但另一些人则认为_。There is a public controversy nowadays over the issue of . There who criticize .argue that ., they believe that .,but people who favor ., on the other hand, argue that.目前，_问题争议较大。批判_的人认为_

13、，他们认为_，不过，另一方面，赞同_的人则认为_。Some people are of the opinion that. 有些人认为_。Many people claim that. 很多人认为_。A majority of 绝大多数A large number of 很多人Some people contend that . has proved to bring many advantages (disadvantages)有些人认为_有很多有利之处(不利之处)。Those who argue for . say that .economic development of the cit

14、ies.觉得_的人认为，_ 城市的经济发展。Some people advocate that .有些人在坚持认为_。They hold that . 他们认为_。People, who advocate that ., have their sound reasons (grounds)坚持认为_的人也有其说法(依据)。Those who have already benefited from practicing it sing high praise of it. 那些从中受益的人对此大家褒奖。Those who strongly approve of . have cogent rea

15、sons for it.强烈认同_的人有很多原因。Many people would claim that. 有人会认为_。People who support . give some or all of the following reasons.那些支持_观点的人列出了如下原因：_。But others hold the view that .但是，另外一些人则认为_。观点的用词：Attitude, opinion, 与其搭配的动词以及词组：Take, have, come up with，set forth, put forward等。But on the other hand, the

16、re are also quite a few people who strongly advocate that.,.不过，另一方面，也有少部分人坚持认为_。But people who are ., on the other hand , maintain that.不过，另一方面，_的人认为_。However, there are a large number of people who hold a different view concerning this case.然而，很多人对此有不同的看法。问题用词：Issue, phenomenon，后接介词, on, over等。Howe

17、ver, some others argue that. 然而，另一些人则认为_。However, there are also some others who contend that.然而，也有人认为_。But other people set forth completely totally different argument concerning this case.不过，对于此，另一些人则持完全不同的观点。Some people examine this issue from another angle.有的人用另一角度来看这一问题。On the other hand, there

18、 are also many opponents who strongly .另一方面，也有很多反对的人，他们认为_。According to my personality and fondness, I would prefer . rather than.根据我的个性以及兴趣，我选择_而不会选择_。Personally, I side with the latter (former) opinion.就我个人而言，我支持后者(前者)_。Personally, I am in favor of the former point of view.就我个人而言，我较同意前一种看法。To my p

19、oint of view 我认为To my mind, the advantages far overweigh the drawbacks(disadvantages, shortcomings)我认为，优点胜过缺点。For my part, I stand on side of the latter opinion that.就我而言，我较赞同后一种观点_。As far as I am concerned, I am inclined to be on the side of the latter view.在我看来，我较同意后一种观点。After a thorough considera

20、tion, for my part, I am in favor of the latter view that. 经过深思熟虑，我较支持后一种看法，亦即_。If asked to make a decision, I would prefer.如果真的需要作出选择，我宁愿_。展现问题篇问题的常用词：question, problem, issueRecently, the issue of . has been brought into public focus.近来，_的问题引起了社会的广泛关注。Now we are entering a brand new era full of opp

21、ortunities and innovations, and great changes have taken place in peoples attitude towards some traditional practice.现在我们进入了一个充满机遇和创新的崭新时代，很多人对某些传统的看法也发生了很大改变。Recently the issue of whether or not . has been in the limelight and has aroused wide concern in the public.近来，是否_的问题已经非常明确而且引起了社会的广泛关注。The i

22、ssue whether it is good or not to . has aroused a heated discussion all over the country._的利与弊已在全国范围内引起热烈的讨论。At present, some people think .while others claim .Both sides have their merits.目前，一些人认为_而另一些人则认为_。其实，两种观点都其可取之处。People rarely reach an absolute consensus on such a controversial issue.对于这种极具

23、争议的话题，我们很难作出绝对的回答。People from different backgrounds would put different interpretations on the same case.不同行业的人对同一种问题的解释不尽相同。The controversial issue is often brought into public focus. People from different backgrounds hold different attitudes towards the issue.这中极具争议性的话题往往很受社会的关注。不同的人对此问题的看法也不尽相同。W

24、hen asked ., some people think. while some prefer.说到_，有人认为_，而另一些人则认为_。Just as the saying goes: so many people, so many minds. It is quite understandable that views on this issue vary from person to person.俗话说，。不同的人对此有不同的看法是可以理解的。To this issue, different people come up with various attitudes.对于这个问题，不

25、同的人持不同的观点。There is a good side and a bad side to everything, it goes without saying that.万事万物都有其两面性，所以，勿庸置疑，_。When it comes to ., most people believe that ., but other people regard .as .提到_问题，很多人认为_，不过，一些人则认为_是_.When faced with., quite a few people claim that ., but other people think as.提到_问题，仅少数人认为_，但另一些人则认为_.