课上,我首先和学生一起回忆长度单位、面积单位、质量单位之间的进率,为本节课的学习打下基础。接下来由易到难,先尝试由低级单位的单名数改写成高级单位的单名数的题目,引导学生归纳低级单位的单名数改写成高级单位的单名数的方法是除以进率。然后通过尝试由高级单位的单名数改写成低级单位的单名数的例子.归纳总结高级单位的单名数改写成低级单位的单名数的方法是乘进率。
通过练习,学生掌握了单名数之间的改写方法后,尝试单名数与复名数之间的改写,引导学生在做这类题时,要看清楚是什么名数改写成什么名数,如果是复名数改写成高级单位的单名数,复名数中高级单位前面的数应写在单名数的整数部分,只需要把复名数中低级单位进行改写;如果是高级单位的单名数改写成复名数,要把原小数分成两部分:整数部分写在复名数的高级单位前,小数部分根据各单位间的进率进行改写。这样给学生一个清淅的解题思路,学生解题的正确率自然会提高。
为了让学生熟练掌握,我用一句话简单概括:“高改低乘进率,小数点向右移,低改高除以进率,小数点向左移”。
这堂课,我做得比较好的地方如下:
1、让学生在独立思考、同桌交流的过程中初步感知了名数改写的方法,让学生始终处于学习的主体地位,集中发展学生的思维,让学生自主探索、合作交流中探究、学习新知,从而关注学生学习的整个过程。
2、对于名数的概念,教材中没有明确的介绍,也不是这节课的重点,在学生猜测的基础上,我直接告诉学生:“一个数和单位名称合起来就是一个名数”,再在比较中了解单名数和复名数,学生对名数的\'理解就比较清晰。这样学生很快的就知道了什么是“名数、单名数和复名数”。而单名数的改写我则采用学生先思考尝试后交流,在反馈中进行个别指导的方法,规范语言,归纳方法。这样让每一个孩子都学有所获,让不同的孩子有不同的收获。
3、在整个教学的过程中,尊重学生的思考,对有不同意见的学生,采用鼓励性的语言,让学生充分发表自己的看法,给每个孩子以展示自己的机会,充分调动了学生学习的积极性。
不足之处及改进措施:
1、在教学中也发现,学生虽然对单名数之间的改写方法理解掌握得比较好(高级单位化低级单位乘进率,低级单位化高级单位除以进率),但由于部分学生对于单位之间的进率不熟悉,特别是面积单位之间的进率掌握的不好,致使一些学生在改写时出错。在课前让学生整理长度单位、面积单位、质量单位之间的进率时,应该给学生一定的时间熟悉这些进率,以便提高解题的正确率。
2、个别学生移动小数点不够熟练,解题速度比较慢,尤其是把高级单位的单名数改成复名数或把复名数改成高级单位的单名数,学生出错较多。应在新课前复习一下有关这方面的整数练习题,以便为学生学习新知识做好铺垫。
Fox is with the grape
Hungry of the fox see the grape to up hang the radiant and extremely keen grape of a string, saliva direct current, and want to pick to eat, but again
Can not take off.See in a short while, helplessly walked, and his side walk the side oneself to comfort to by oneself say:" this grape have noes familiar, affirmative
Is sour."
This is to say, and the some person's ability is small, and do to not accomplish anything, borrow to say the opportune moment immaturity.
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Wolf and egret
The wolf mistake swallowed a piece of bone, very suffered, running about, look for to visit the doctor everywhere.He met the egret, and talk to settle the service fees to invite him to take out the bone, egret to stretch in the wolf's throat the own head, and the 叼 outs bone, then toward to settle the good service fees wolfThe wolf answer says:" hello, friend, you can since the wolf 嘴 take back the head in the peace ground, and the difficult way return the dissatisfied foot, and how and still speak the guerdon?"
This story elucidation, guerdon badly person act charitably, and is a bad person of cognition and does not speak the reputation's innate character.
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Little boy and scorpion son
There is a child in front of city wall to catch the grasshopper, and in a short while caught the lots of.Suddenly see a scorpion son, he to think is also grasshopper,
Then two go to catch him.The scorpion son raises his poison to stab, say:" come, if you really dare to do like this, connect your grasshopper that catch to also would entirely lose."
This story warns people, and want to distinguish the pure good man with the bad person, and distinct to treat them.
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Drop at the fox in the well with the 公 goat
An only the fox take a wrong stepped the well, in spite of how he struggle can not still climb up, and have to be foolish there.The 公 goat feels
Thirsty pole, arrive at this well the side, and see the fox under the well, and then ask him the well water the how about it to drink?The fox feels the opportunity to come, heart inside
The 暗 pleaseds, right away the town quiet down, make every effort the laudation well water good drink, say this water is a world the first spring, pure and sweet and good to eat, and advise the goat to hurry up
Come down, and drink to heart's content with him.A the heart think only of to drink the water letter to think the true goat, then the without stopping to think ground jump downed to go to, and be his 咕咚咕 the 咚 painful
After finishing drinking, have to with the fox together totally the company ascend the well's way.Fox early contain preparation, he to archly say:" I pour to have a
Method.You pick with forepaw on the well wall, again Cape 竖直 , I behind carry on the back to jump up the well to go to from you, and pull you again to come up, we all
Save." the 公 goat agreed his proposal, fox to trample the feet of his empress, and jump he carry top on his back, and then make an effort from the Cape a
Jump, jump outed the mouth of a well.The fox go ups the hereafter, and the preparation alone escape.The 公 goat blames the fox and does not keep the 诺 speech.The fox returns overdo
Say to 公 goat:" hello, friend, beard that you of brains if resemble you are so perfect, you not to the extent of at did not see the pure exit it
Front blindly jump down to go to."
This story elucidation, cleverness of the person should to in advance think it over the affair's result, then just go to do.
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译文:
狐狸和葡萄
饥饿的狐狸看见葡萄架上挂着一串串晶莹剔透的葡萄,口水直流,想要摘下来吃,但又
摘不到。看了一会儿,无可奈何地走了,他边走边自己安慰自己说:“这葡萄没有熟,肯定
是酸的。”
这就是说,有些人能力小,做不成事,就借口说时机未成熟。
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狼与鹭鸶
狼误吞下了一块骨头,十分难受,四处奔走,寻访医生。他遇见了鹭鸶,谈定酬金请他取出骨头,鹭鸶把自己的头伸进狼的喉咙里,叼出了骨头,便向狼要定好的酬金。狼回答说:“喂,朋友,你能从狼嘴里平安无事地收回头来,难道还不满足,怎么还要讲报酬?”
这故事说明,对坏人行善的报酬,就是认识坏人不讲信用的.本质。
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小男孩与蝎子
有个小孩在城墙前捉蚱蜢,一会儿就捉了许多。忽然看见一只蝎子,他以为也是蚱蜢,
便着两手去捕捉他。蝎子举起他的毒刺,说道:“来吧,如果你真敢这样做,就连你捉的蚱蜢也会统统失掉。”
这故事告诫人们,要分辨清好人和坏人,区别对待他们。
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掉在井里的狐狸和公山羊
一只狐狸失足掉到了井里,不论他如何挣扎仍没法爬上去,只好呆在那里。公山羊觉得
口渴极了,来到这井边,看见狐狸在井下,便问他井水好不好喝?狐狸觉得机会来了,心中
暗喜,马上镇静下来,极力赞美井水好喝,说这水是天下第一泉,清甜爽口,并劝山羊赶快
下来,与他痛饮。一心只想喝水信以为真的山羊,便不假思索地跳了下去,当他咕咚咕咚痛
饮完后,就不得不与狐狸一起共商上井的办法。狐狸早有准备,他狡猾地说:“我倒有一个
方法。你用前脚扒在井墙上,再把角竖直了,我从你后背跳上井去,再拉你上来,我们就都
得救了。”公山羊同意了他的提议,狐狸踩着他的后脚,跳到他背上,然后再从角上用力一
跳,跳出了井口。狐狸上去以后,准备独自逃离。公山羊指责狐狸不信守诺言。狐狸回过头
对公山羊说:“喂,朋友,你的头脑如果像你的胡须那样完美,你就不至于在没看清出口之
前就盲目地跳下去。”
这故事说明,聪明的人应当事先考虑清楚事情的结果,然后才去做。
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一天,阳光明媚,风和日丽。真是一个好天气!小熊、小象、小鸭、小鸟和小猴在森林中快乐地玩耍嬉戏。
它们正在玩捉迷藏。小象蒙上眼睛,慢慢摸索着小动物们,小鸭回过头,注视着小象,脚步慢慢向前移。忽然,“哎呀”一声引起了小动物们的注意,小动物们这才发现:小鸭子原来掉进了坑里,它正在坑里痛苦地挣扎着呢!小动物们急得团团转,简直就像热锅上的蚂蚁一样!
小鸟叼来草,试图用草拉起小鸭子,可是草太柔软,被拉断了。小猴折下一根光滑的树枝,可是树枝太光滑,小鸭没救成,小猴自己摔了一跤。这时,机灵的`小熊想出了一个绝妙的主意。原来小鸭子游泳特别好,只要把土坑里灌满水,小鸭子就能浮上来!于是,小熊提着水桶去提水,小象用长鼻子吸足水,猛地往坑里喷水。不一会儿,坑就灌满了,小鸭子终于得救了!
小鸭子十分感激其它小动物,这时,小动物们终于知道了:友谊才是最珍贵的!
Wolf, meeting with a Lamb astray from the fold, resolved not to lay violent hands on him, but to find some plea, which should justify to the Lamb himself his right to eat him. He thus addressed him:"Sirrah, last year you grossly insulted me." "Indeed," bleated the Lamb in a mournful tone of voice, "I was not then born." Then said the Wolf, "You feed in my pasture."
"No, good sir," replied the Lamb, "I have not yet tasted grass." Again said the Wolf, "You drink of my well." "No," exclaimed the Lamb, "I never yet drank water, for as yet my mother′s milk is both food and drink to me." On which the Wolf seized him, and ate him up, saying, "Well! I won′t remain supperless, even though you refute every one of my imputations."The tyrant will always find a pretext for his tyranny.
狼和小羊
一只狼瞧见一只迷路失群的小羊,决定暂缓下毒手,想先找一些理由,对小羊证明自己有吃它的权利。它就说:「小鬼!你去年曾经骂过我。」小羊可怜地说:「老实说,我去年还没有出生呢。」狼再说:「你在我的草地上吃过草。」
小羊回答说:「不,好先生,我还未曾尝过草的味道呢。」狼又说:「你喝过我井里的.水。」小羊叫道:「不,我从没有喝过水,因为直到今天为止,我都是吃着母亲的奶汁。」狼一听这话,便抓住它,把它吃下去,便说:「好!即使你驳倒我每一句话,我终究要吃晚餐的!」暴君总有他暴行的借口。
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