口算除法教案冀教版

2024-12-24 版权声明 我要投稿

口算除法教案冀教版(精选8篇)

口算除法教案冀教版 篇1

素质教学目标: 知识与技能

1.能正确口算整十数除以一位数,并能掌握用竖式计算的方法。2.培养学生的举一反三能力,能口算整百整千数除以一位数。过程与方法

结合小棒引导学生经历探索整十数除以一位数计算方法的过程。情感、态度与价值观:

1.培养学生的观察能力、操作能力和初步逻辑思维能力。2.丰富提升学生的生活经验,发展数学应用意识。教学重点:能正确进行口算。

教学难点:掌握除法口算的思维方法,理解算理。教 具:口算卡片 图片 学 具:学生每人60根小棒。教学过程: 1.复习

8÷4= 35÷5= 9÷3= 24÷6=

80里有()个十,400里有()个百。46里有()个十和()个一。39里有()个十和()个一。2.揭示本课课题:1.口算除法

二、新课教学

1.教学例1:分一分。

(1)电脑演示:把10根小棒捆成一捆,共有6捆,也就是60根,边演示边提问:把60根小棒平均分成3份,求每份是多少?用什么方法计算?怎样列式?(老师板书:60÷3=)继续演示:把6捆平均分成3份,每份分得2捆,也就是20根。

(2)请小朋友摆出6捆小棒,每捆10根,也像这样分一分。(3)教学60÷3的口算过程。

师:刚才大家动手分了,现在来动脑:60除以3口算时该怎样想呢?可以这样想:60是几个十?6个十除以3得几个十?2个十就是多少?所以60÷3等于多少?随着学生的回答教师板书:想:6个十÷3=2个十=20。请同桌互相说一说60÷3的口算过程,再请两名学生说一说。(把60根小棒平均分成4份,求每份是多少?)(4)反馈练习(出示卡片):80÷2= 90÷3=(5)尝试口算(板书):600÷3= 6000÷3=

(6)小结:像这样整

十、整百、整千数除以一位数,在口算时可以把被除数看作几个

十、几个百、几个千去除以一位数,计算出结果就是多少个

十、百、千。(7)介绍除法算式的另一种读法。

师:(指60÷3)哪位小朋友来读读这个算式?(生:60除以3)(板书:读作60除以3)60除以3,这是一种读法,它的特点是先读被除数后读除数;如果先读除数,后读被除数又该怎样读呢?也可以读作“3除60”,请跟老师读一遍。(生读,师板书:3除60)谁能用两种读法读这个算式。(8)学生试用两种读法读600÷3 6000÷3(9)教学竖式书写方法。学生练写。

a.(电脑出示)用两种读法读下面的除法算式,再口算。40÷2=(请女同学读,一人口算出得数)500÷5=(请男同学读,一人口算出得数)8000÷2=(全班一起读,一起口答)

三、看书,质疑

四、练一练(电脑出示)a.对比练习。

90÷3 70÷5 63÷3 50÷2 80÷5 72÷4 b.出示生活应用题

冀教版五年级数学上册口算练习 篇2

0.02×0.5= 3.6÷0.3= 6.3÷7= 5.6÷100= 0.75÷0.25= 0.125×8= 4.8÷0.3= 0.96÷2= 0.56÷28= 0.36÷0.4= 0.64÷0.8= 0.72÷3.6= 2.4×0.5= 0.8×1.1= 7.2+12.8= 46.7-3.8= 12.8÷4= 5.2÷13= 12.5÷5= 1.64÷41=

3.6÷0.18= 1.5×0.4= 1.25×8= 0.6×0.5= 0.25×0.4= 3.5÷0.07= 4.7+2.3= 4.5×2= 6.9-2.5= 7.2×0.8= 6×3.4= 0.62-0.32= 1.4×0.5= 0.75×100= 0.026×100= 10÷20= 24÷15= 8.65×10= 0.35×0.6= 3.08×0.01=

9.6÷0.8= 0.108÷2= 4.95÷0.9= 9.65÷0.1= 0.325×100= 2.5×8= 0.56÷0.7= 0.125×4= 3.28×0.1= 3.9÷0.13= 7.2×0.1= 0.01×0.1= 0.25×0.4= 1.6÷0.8= 0.25×3.97×4= 1.25×0.8=(1.2+8.8)×0.4= 0÷1.7= 9÷0.25÷4= 1÷2.5=

3.2×0.4= 0.3÷0.01= 4÷0.5= 5.1÷0.17= 0.28÷1.4= 0.9÷0.45= 9.6÷16= 1÷0.01 =

0.01÷1= 7.5÷1.5= 0.81÷9= 3÷0.5=

10÷25= 4.8÷0.16= 0÷3.89= 3.52÷1=

6.4÷4﹦ 1.5÷0.3﹦ 1×0.4÷1×0.4= 1.8×5﹦

7.2÷0.9﹦ 25×4÷0.25×4= 2.2×6﹦ 8.4÷0.4﹦

4.5÷0.9﹦ 2.5×4﹦ 25×3.3×0﹦ 2.5×4﹦ 0.3÷0.1﹦ 4.5×2= 7.8+0.22= 2-0.64-0.36﹦

3.4×0.4= 12.6-0.9= 2-1.64-0.36﹦ 1.2÷0.04= 0.42÷7= 1.25×3.3×0﹦ 0.9+2.01= 2.97÷100=

20-3.7-7.3= 6.3+7= 2.19+9.1= 0.65×0.2= 9.8-0.98= 1-0.1×0.1= 0.7+3= 1.2×0.8= 0.9×7+10.7= 6.3÷0.021= 1.5÷0.03= 6.8-2.4÷3= 5×0.7= 0.43×5= 3.6÷0.9-4= 3.6-0.36= 8.1-2.2= 0.6÷0.3+0.5= 6.8+8.6= 9.4×0.2=

1.8÷0.9= 2-1.08= 8.8÷0.4= 43×0.01﹦

3.72×0.2= 0.7×8= 99+0.1﹦ 3.2-2= 6×0.125= 1.9×4﹦ 8.8÷0.11= 4×1.2×0.25= 0.125×8﹦0.05×4= 4.23.72÷4= 1.13.2×50= 3.21.29÷3= 1.210.7-5.7= 0.01×100= 1.2-0.9= 20×0.4= 7-2.5×4= 6÷10= 6.4÷8= 0.24×0.5= 3.2-0.9= 0.12

×40= 2.3÷0.1﹦ 8×5.1= ×3﹦ 2.01÷3= 1.8÷0.3=

×0.7= 2.32-0.4= 5.1÷51= ×0.5= 0.01÷0.1= 1.25÷0.5= ×3= 2-0.8= 55×0.06= 0.52+0.08= 2÷5= 8×0.03= 30×0.01= 0×1.22= 0.6×5= 九

0.54÷0.6= 0.26×0.3= 1÷0.05= 0.9= 16÷0.4= 0.14×5= 3.2÷0.8= 0.45+0.55= 5.1÷0.3= 0.2×12= ×6= 15÷2= 4.95×1000= 3 1.8

6.9×0.1= 0.4×0.5= 2.4÷0.8= 10.8÷9= 3.2÷0.04= 5.6÷1.4= 0.48÷0.8= 4.4÷0.11=

4.2×3 = 0.16×5 ﹦ 1.78×2.2 = 1.2×5= 0.7×0.01= 2.55.37×5= 9.616.9×0.3= 2.370.78×5 = 54.39×10= 4.3912×0.03= 0.037.3×5= 0.10.05×0.8=1.3×0.4= 13.53.6×0.09= 2000.42×0.6=0.5×0.7 = 0.8

×0.4 = 1.25×8= 6.6×0.6 = ×0.6 = 5.3×2 = 5.5×3=

十一

+6.3= 2.37+3.7= 2.64×5= ×0.78= 5.3×42= 1×0.125= ×0.1= 0.7×2 3= 0.47×0.7= ×0.12= 3×0.121= 8.6×0.7= ×0.2= 3.57×5= 4.2×0.1=

十二

×3= 7.5×2.5×4= 1.2×0.4= × 6 = 0.75×0.5= 3.5×0.1=

×0.04= 12-1.2= 1.3×0.5=

×0.5= 0.21×0.3= 2.5-1.37= ×3.2= 1.5×4= 5×4.8= 4 1.23 3.2十三

0.75+0.8= 0.13×4= 8.5×100= 5.4×10= 4.2×1000= 3.2×100= 3.6×0.1= 0.18×0.3=

1.2×0.3= 0.49×0.7= 0.04×25= 42.4+7.6=

1.58+2.42=3.9+2.7= 0.241.25×8= 5.70.24×0.3= 0.27×1.3= 0.364×0.5= 72.4×0.8= 91-0.82= 9.64.8×0.4= 5.4+4.6?2= 9-3.2=(1.5+2.4)1.3×0.4= 8.59.5×0.1= 0.125×1= 4.39

-5.6= 1.25×4= 7.8×0.5= ×0.3= 2.5×4= 0.3×10=

十四

×5.7= 0×4.8= 12-3.8= ×0.5= 2.5×3= 4.4×(5×0.2)= ×0.3= 0.35×0.7= 0.7×0.7= ×2.1= 8.89+0.1= 0.1×0.01= ×0.4= 10×0.01= 4.3-0.25=

十五

×0.3= 2.6×0.01= 0×25.4=

×0.2= ×0.5= 7.2×0.8= 5.4×0.6= 10×2.5= 35×0.05= 0.64×0.4= ×10= 4.39÷0.1= 0.7×2= 5 7.8十六

2.5×0.5= 6.45×0.01= 0.36×0.3= 0.8×0.001= 0.01×0.2= 7.5×2.5= 8.8×0.2= 0.96×6= 0.75×0.5= 0.7×5= 0.08×1000= 0.1×6.7= 1.6×0.5= 2.5×4= 0.74×0.4= 7.5×3= 0×25.4= 4.8×0.4= 7.5×2.5×4= 1÷0.125=

十七

3.74×0= 0.8×0.6= 0.05×0.08= 80×1.25= 0.13×7= 3.5×4= 2.8×0.5 3.5×200=

0.75÷15= 0.4×0.8= 4×0.25= 0.36+1.54= 0.05×4= 4×0.3= 12.5×8= 2.3×4= 3.25×0= 2.6×3= 7.5×0.1= 1.25÷0.25=

十八

0×9.8= 3÷4= 3.5×0= 1×0.06= 2.6×3= 7.5×0.1= 9×0.5= 8.2+1.8= 2.4×5= 3.99×1= 8.4÷7= 8.4÷0.7= 0.34÷0.17= 30.4÷4= 1.2×6= 0.72÷0.6= 2.6÷1.3= 0.6×0.3= 0÷3.65= 7.82÷1 =

十九

0.001÷0.1= 1.4÷0.7= 3.6÷0.06= 5.6÷0.9=

5.6÷1.4= 0.48÷0.8= 4.4÷0.11= 4.2×3 = 3.2×0.4= 0.3÷0.01= 4÷0.5= 5.1÷0.17= 0.28÷1.4= 0.9÷0.45= 9.6÷1 1÷0.01 =

0.01÷1= 7.5÷1.5= 0.81÷9= 3÷0.5=

二十

10÷25= 4.8÷0.16= 0÷3.89= 3.52÷1=

37.2×99+37.2= 6.4÷4﹦ 1.5÷0.3﹦ 1.8×5﹦

7.2÷0.9﹦ 2.2×6﹦ 8.4÷0.4﹦ 3.2×0.8= 2.5×0.5= 2.03×2= 1.65×0.5= 0.9×0.4= 0×5.8= 0.36×0.9= 1.62×0.4= 2.5×0.5=

二十一

0.05×0.8= 1.23×3= 7.5×2.5×4= 1.2×0.4= 2.8×0.4= 2.5×0.4= 1.2×5×8 = 5.37×0+4.63 = 2.4×0.3 = 2.03×2= 4÷0.5= 7×2.1= 8.89+0.1= 0.1÷0.01= 2.4×0.8= 9×0.4= 10×0.01= 1-0.82= 9.6÷0.3= 2.6×0.01=

二十二

0.7×0.7= 0.7+0.7= 0.3×1.21= 3×1.21= 7.8-5.6= 1.25×4= 7.8×0.5= 0.24÷0.3=

2.5×4= 0.3÷10= 1.25×8= 5.7÷5.7=

0÷4.8= 77580÷290=(8.699×0.35= 0.058.5×100= 5.40.45÷0.15=0.49÷0.7= 8.50.36÷0.03= 0.088.8÷0.2= 0.96 0.08×1000= 0.10.74×0.4= 7.51.3×0.4= 5.4÷0.6= 9.5÷0.1= 10÷2.5= 35÷0.05=

÷7.7= 7.3÷0.5= 5.8+1.4)×18= 0.1×0.2=二十三

×0.8= 1.23÷3= 0.36÷10= 4.2×1000= 2÷0.1= 18×0.3= 1.2÷1.7= 0.04×25= 6.45÷0.001= 0.01÷0.2= 7.5二十四

÷6= 0.75÷0.5= 0.7×6.7= 1.6×0.5= 2.5×3= 0×25.4= 3.6×2= 8.5÷0.5= ÷0.29= ÷0.1=

÷12= ÷100=

÷0.3=

÷0.01= ÷2.5=

×5=

×4= 4.8×0.4= 7.2÷0.8= 8

4.2 3.6 单元梳理课

一、单元梳理课的定义

单元梳理课是在学生经历了某单元或某一阶段的学习后,学生在教师的引领下,自主、合作梳理单元知识与技能、构建数学思维网络。这节课不是简单地知识与回顾,而是学生们自主梳理,展示自我的舞台,学生在相互交流、分享、展示和评价的过程中,将一单元的知识形成整体的网络系统,发现、提出、分析、解决问题能力得到进一步的提高。

二、单元梳理课的意义

1、单元知识梳理能够加深学生对知识的理解。

2、单元知识梳理可以使知识系统化。

三、单元梳理课的原则

1、关注梳理方法。

2、鼓励学生自主、合作梳理知识。

3、注重学生数学水平的提高。

四、单元梳理课的特点

1、再现性。

2、概括性。

3、系统性

4、综合性

五、单元梳理课的教学流程

1.课前自主梳理。这部分内容教师课前要根据班级学生的实际情况和本单元的重、难点,精心设计课前尝试小研究作业,内容包 括知识点的梳理以及典型题和易错题的梳理。学生梳理的形式不限,可以是文字式、表格式、画图式等,总之放手让学生采取个人喜欢的方式进行梳理,调动学生的积极性和主动性。2.组内交流完善梳理。在交流的过程中,吸取他人的长处,比如知识点整理的疏漏,解题技巧的妙招,透过生生的思维碰撞,完善个人的知识梳理,解决小组中同学之间存在的问题。3.班级交流提升梳理。各小组汇报小组中的知识梳理,提出本单元应该注意的问题以及典型题和易错题等,形式可以是展示,提问和质疑等多种形式。这一环节有助于学生进一步领略单元知识的全貌,有利于思维的撞击和智慧火花的迸发。

4.应用拓展。教师根据本单元的知识结构,题型特点及易错、易混题型,设计层次不同、形式多样的练习题,帮助学生强化所学知识,提高教学效果。

口算除法教案 篇3

十、整百、整千数的口算方法:

(1)用表内除法计算:用被除数0前面的数除以一位数,算出结果后,看被除数的末尾有几个0,就在算出的结果后添几个0。

(2)想乘法,算除法:看一位数乘多少等于被除数,乘的数就是所求的商。

2、一位数除几十几、几百几十或几千的口算方法:用被除数的前两位除以一位数,在得数的末尾添上与被除数末尾同样多的0。

1、口算

60÷3= 800÷4 720÷8= 200÷4= 69÷3= 864÷2 例

2、把66张彩色手工纸平均分成3人,每个人得到多少张?

3、学校一共有400名学生,把他们平均分成8组,每组有多少人?

4、学校买回6梱书,每梱40本,把这些平均分给8个班,每个班可分书多少本?

1.口算

25÷5= 63÷7= 42÷6= 24×4= 250÷5= 600÷3= 77÷7= 630÷7= 240÷8= 2800÷7= 4000÷5= 800÷2= 63÷3= 84÷4= 100÷2= 420÷6= 2.填空

(1)630÷7,可以把630看成()个十,()个十除以7等于()个十,也就是();还可以想:因为()×()=(),所以630÷7=()。(2)有72朵红花,9朵黄花,红花是黄花的()倍。3.学校一共有300名学生,把他们平均分成6组,每组有多少人?

4.公园运来240盆花,准备摆在4个花坛里,平均每个花坛摆多少盆?

5.三年级学生去农场劳动,女生去了156人,男生去了124人,4人分一组,一共可以分多少组?

1、口算

6÷3= 4÷4= 3÷3= 6÷2= 88÷4= 60÷3= 400÷4= 33÷3= 66÷2= 888÷4= 600÷3= 4000÷4= 330÷3= 660÷2= 880÷4= 64÷2= 369÷3= 270÷3= 4000÷8 1000÷2= 2、400÷5,可以把400看成()个十,()个十除以5等于()个十,也就是();还可以想:因为()×()=(),所以400÷5=()。3、27的3倍是(),48是3的()倍,3的()倍是69,4、一个正方形周长是80厘米,边长是多少厘米?

《口算除法》教案doc 篇4

【教材分析】(1),教学整十数除整十数口算。教材呈现了学生喜闻乐见的分气球情境,给出“有80个气球”“每班20个”的信息,要求解决“可以分给几个班?”让学生得出80÷20的口算式题。进而让学生探索口算的方法,课堂中教师要让学生充分利用已有的口算知识,自主探索出教材所呈现的两种方法,一种是根据乘除法关系用乘法算除法(即想20×4=80,算80÷40=2),另一种是用表内除法计算(想8÷2=4算 80÷20=4)。为给试商做准备,如果学生只想到其中的一种口算方法,教师要适当加以引导和深化。口算方法的得出教材还专向安排了相应的除法估算如 83÷20,80÷19,使学生获取更为有效的知识体系。例1(1)下面的“做一做”编排了3组相应的精算与估算式题,通过每组上下有联系的式题口算,意在帮助学生获取基本的估算方法。例1(2)是教学整十数除几百几十数的口算。它的编排体系与例1(1)很相似,教师可以放手让学生自己探索口算方法,在学生口算之后教材也一样安排了相应的整十数除几百几十数的估算与精算。

【教学目标】

1、使学生理解和掌握整十数除整

十、几百几十的数(商一位数)的口算方法,能正确地进行口算。

2、使学生经历探索口算方法的过程。

3、让学生感受数学与生活的联系,培养学生用数学知识解决简单实际问题的能力。

【教学重点】

1、探索口算方法;

2、掌握用整十数除的口算方法。

3、估算方法

【教学难点】

1、理解算理的基础上掌握口算的方法。

2、理解除的算理,正确进行口算。

【课前准备】

【课时安排】2个课时。主要学习内容安排如下:

第一课时:

第二课时:

【教学过程】

第一课时

教学过程:

一、复习

1.填空。

20×4=80表示()个()是()。

70×3=210表示()个()是()。

90里有()个十。

280里有()个十。

2.口算:

20÷4 42÷7 70÷7 63÷9 30÷5 81÷9 180÷6 60÷5

二、操作交流,探讨算法

1.教学例1(1)。

(1)多媒体出示分球的情景:“80个气球”、“每班20个”的条件。

(2)再出示:这些气球可以分给几个班?大家想一想:怎样列式呢?(80÷20)为什么这样列式?该怎样口算?

(3)估算:83÷20≈ 80÷19≈

想:做加减法估算时是怎样估算的?(分组讨论,汇报结果)

小结估算方法:两位数除法的估算,一般是把两位数看作与它比较接近的整十数,再口算出结果。

(4)练习(79页做一做)。

2.教学例1(2)。

(1)用多媒体出示分彩旗的情景:有20面彩旗,每班30面,可以分给几个班。

(2根据画面口头编题,想一想怎样列式?(120÷30)为什么这样列式?该怎样口算?

(3)想一想:122÷30≈ 120÷28≈

学生说出估算的依据,并说出为什么这样估算?最后归纳出估算的方法。

(4)79页做一做。

课后专项练习。评价优胜。

(5)增加练习(教师可根据本班实际进行取舍性习题)

A.

B.

板书设计:

一、复习

1.填空。

20×4=80表示()个()是()。

70×3=210表示()个()是()。

90里有()个十。

280里有()个十。

2.口算:

20÷4 42÷7 70÷7 63÷9 30÷5 81÷9 180÷6 60÷

5第二课时

教学过程:

一、口算大操练

1.听算:

30÷10 60÷30 80÷40 240÷60

210÷70 300÷50 270÷90 630÷70

你是怎样口算的?

2.口算:(80页练习十三第1题)

学生独立完成后评讲。

3.视算:(80页练习十三第4题)

学生独立完成后,提问:≈表示什么?

本题的口算与第1题的口算有什么不同或相同?

本题第一行的口算和第二行的口算有什么异同?

二、实际操作台

1.80页练习十三第2题

要求学生根据画面内容,口头编一道除法应用题。列出算式解答。

2.80页练习十三第3题

提问:限载40人是什么意思?

根据画面编一道应用题,学生自己独立列式完成。

教师根据算式提问:为什么用除法计算,你是怎样计算的?

3.80页练习十三第5题

提问:大约表示什么?为什么这道题要用大约?

学生独立列式,教师讲评。

4.小蜜蜂花蜜

板书设计:

听算:

30÷10 60÷30 80÷40 240÷60

210÷70 300÷50 270÷90 630÷70

教学反思

在这次有效课堂教学活动中,我讲得是口算除法,上课一开始我就对旧知识进行了复习,复习的目的是为了回忆学生已有知识,找出本课学习要用到的知识,利用旧知来导新的知识,进行知识的迁移。复习内容是20×4=,30×4=。要让学生想到用乘法口诀算出: 2×4=8,这里的2表示2个十,2个十×4=8个十,所以20×4=80。接着又出除法算式,80÷4=,120÷4=,同样也让学生说出想法,本节课的教学重点难点:通过自主探究学会口算的方法,能正确的进行口算。新知的学习中,先让学生观察情景图,大大激发了学生的学习习惯和参与意识。先让学生根据图中信息提出数学问题,再列出算式,并问学生为什么要用除

法来计算呢?并让生说一下除法的意义,接下来让学生自主探究如何口算,独立思考口算方法,把想法和同桌讨论交流,充分体现算法多样化,并对学生说明,用自己喜欢的方法口算,学生学得轻松,又通过倾听和交流得到了发展,口算能力也得到了提高。让学生多去说一下。接下来第二道就让学生自己去完成。

在练习时,先出示练习的第一题,让学生完成,然后让同桌说出口算的想法,在指名说一道看一看问题大不大,当时学生反应不大,我就放慢速度,让不同层度的学生都说一说,接着效果就好点。后面的题学生能够积极回答,这几题我只是让学生对了一下。类似的,在平时的学习中,经常采用这样的方法,当学生出现呆滞时,就要调整策略。

三年级“口算除法”数学教案 篇5

教学目标:理解与表内除法相应的一位数除几百几十和几千几百的口算方法,并能正确地进行口算。

教学重、难点:培养学生初步的分析、综合和类推等思维能力。

教学具准备:小黑板、投影片。

教学过程:

一、复习。

1.口算。

18divide;424divide;212divide;3

2.填空。

210里面有个十,

1200里面有()个百。

120里有()个百和()个十,也可以看作()个十。

二、教学新课。

1.教学120divide;3。

(1)学生摆出1大捆和2小捆小棒。把120根小棒平均分成3份可以怎样想?

(2)把12个十平均分成3份,每份是几个十,就是几十?

(3)说一说120divide;3你是怎样想的?

(4)口算。

做“练一练”第1题。

学生口算,并说一说想的过程。

2.教学“试一试”。

(4)出示1200divide;3。

说一说,1200divide;3口算要怎样想?

(2)做“练一练”第2题。

学生算出得数。

指名口答是怎样想的?

三、巩固练习。

1.练习七第6题。

学生先独立完成,集体订正。

2.练习七第7题。

学生先独立完成,集体订正。

四、课堂小结。

本节课你学会了什么?

五、课堂作业。

口算除法教案冀教版 篇6

1.使学生理解和掌握整十数除整十数、几百几十的数(商是一位数)的口算估算方法,能正确地进行口算和估算。

2.使学生经历探索口算方法的过程,交流、讨论理解算理。

3.让学生感受数学与生活的联系,培养学生用数学知识解决简单问题。

学情分析:

使学生在理解和掌握除数是一位数的口算估算方法的基础上,进行循序渐进的学习。把数学知识与日常生活紧密结合在一起,能激发学生的学习兴趣。让学生感受到,数学来源于生活,应用于生活。

重点难点:

掌握口算除法的算法;经历探索口算除法算法的过程。

【测试】

复习旧知识

1.口算,说出口算过程。

8÷2= 15÷3=

除数是一位数的口算方法:可以想乘法算除法。

2. 估算,说出估算过程。

83÷2≈ 118÷6≈

( ) ( )

除数是一位数的估算方法:根据“四舍五入”法,把被除数看做与它接近的整十或整百整十的数,再口算出结果。

【导入】

口算除法

前面,我们学习了除数是一位数的口算和估算。通过检验,老师发现同学们对于学过的知识,都还有一定的记忆,这非常棒!老师也希望,同学们在以后的学习中,能经常把学过的知识,进行不断的整理和复习,这样不仅能把知识加深印象,而且会更有利于新知识的学习。

这节课,我们来一起继续学习口算除法。不过,本节课的口算除法,可是有难度的,你们敢挑战吗?

【讲授】

讲授新知

1.猜一猜。6月1日是什么节日?(儿童节)

2.学习例1.(1)

师:瞧,老师手里拿着什么?(彩旗)学校有80面彩旗,每班分20面。

根据这些信息,你能提出什么数学问题? (可以分给几个班?)

用什么方法计算?怎么列式呢?(用除法计算,算式是80÷20)

怎样口算80÷20呢?请大家分组交流、讨论,再互相说说口算方法。

a.由20×4=80,得出80÷20=4,(想乘法算除法)

b.8÷2=4,得出80÷20=4 (想表内除法算除法)

学生讨论,你喜欢哪种方法?说说你的理由。

将单位及答补充完整。

3、想一想。83÷20≈ 80÷19≈

4、练习。(我会算)

60÷20= 80÷40=

62÷30≈ 80÷38≈

(1)过渡: 同学们,我们在口算除法的时候,可以选择自己喜欢的方法。刚才我们顺利解决了分气球的问题,大家表现得非常棒。瞧,学校又买来了彩带,(出示情景图)你从图上了解到什么信息?请提出有关的数学问题。

(学校买来120面彩旗,每班分30面,可以分给几个班?)’

师:同学们,你们能解决这个问题吗?在练习本上把算式写出来。

(用除法计算,算式是120÷30)

师:怎样口算120÷30呢?同桌间互相交流,说一说。

a.12÷3= 4 则120÷30= 4 (把120看成12个10,30看成3个10.这里强调让学生进行说一说他的算法过程是怎么想的,揭示本课的的教学目标)

b.30×4=120,则120÷30= 4

(2)将单位和答补充完整。

6、练习。

7、想一想。122÷20≈ 120÷28≈

8、小结。

除数是整十数的口算方法:

除数是整十数的口算除法,可以想乘法算除法;也可以先不看数中个位上的0,想表内除法算除法。

除数是整十数的估算方法:

把两位数或三位数看作与它比较接近的整十数或整百整十的数再口算出结果。

【练习】

巩固新知

1、我会填。

(1)口算420÷60,想42÷6=( ),所以420÷60=( )。

(2)183÷20 ≈( ),241里面大约有( )个40。

(3)一个数的40倍是160,这个数是

2、我会做。

3、生活中的数学。

四年级255人去春游,每辆车限坐50人。要派几辆车呢?

【活动】

课堂总结

1、这节课,你有什么收获?

2、你还想说点什么?

【活动】

板书设计

口算除法

80÷20=4(个)

(1)20×4=80 80÷20=4

(2)8÷2=4

口算除法教案冀教版 篇7

教学目标:

1.巩固用一位数除的口算、估算的方法,提高计算能力,会用除法估算和

口算解决生活中的简单实际问题。

2能根据倍的意义,解决有关倍数关系的实际问题。

3.在解决问题的过程中获得成功的.体验,树立学好数学的自信心。

教学重点:巩固用一位数除的口算、估算方法。

教学难点:正确合理地进行除法估算;正确解决有关倍数关系的实际问题。

教学过程:

一、谈话引入

前两节课我们分别学习了除数是一位数除法的口算和估算,这节课我们专门来进行有关练习,来进一步巩固除法口算和估算的方法,另外还要用口算或估算

的办法解决实际问题,看谁最有收获。

二、组织练习

1.专项练习

(1)口算

第一组:

30÷3400÷29000÷3

60÷2800÷45000÷5

学生先口算,再从各列中任选一个算式说说口算方法。

第二组:

16÷2=30÷5=21÷7=

160÷2=300÷5=210÷7=

1600÷2=3000÷5=2100÷7=

第三组

6÷2=8÷4=9÷3=

72÷9=36÷6=32÷8=

先口算,再观察每列中三道算式,说说有什么发现;比一比第一、第二列,说说有什么变化,为什么?

(2)估算

第一组:

71÷8181÷2359÷6

440÷9138÷7323÷4

先独立估算,有困难的可以找老师帮忙,或把难题直接写到黑板上。集体交流,如果出现不同的方法,只要合理都予以肯定。

第二组:用你喜欢的方法估一估。

125÷2297÷4378÷5435÷7469÷8194÷6

学生练习后交流。

2.解决问题

(1)教科书第17页第4题。

学生读题后问:本题你准备用什么方法解决,可以用哪种计算?(口算、估算)

指名板演,集体校对。

(2)教科书第18页第6题。

学生独立填写空格后,交流各自的想法。

小结:有关倍数关系的问题中,求一倍数的要用除法去计算。

(3)第18页第7题。

有几种解决问题的方法?

你会计算56÷4和64÷4吗?我们后面将学习他们。

(4)挑战题:a第18页第8题。

B找规律填数

481632

24381279()

25112347(),

824123618()

三、课堂小结

今天你又有什么收获?你现在是怎样看待除法口算、除法估算的?

四、作业布置

口算除法教案冀教版 篇8

Teaching Content:

Mastery words and expressions: rather, shower, rise, rose, risen, set

Oral words and expressions: thunder, storm, sunrise, sunset

Teaching Aims:

Talking about weather

Teaching Important Points:

1. Describe the weather in spring;

2. Talk about the temperature.

Teaching Difficult Points:

Describe the nature phenomenon.

Teaching preparation: the pictures of spring

Teaching Aids: audiotape; flashcards; pictures

Type of lesson: new lesson

Teaching Procedure:

Step1. Free talk

1.What weather do you like? Why or why not?

2.What sports can you do in this season?

Step2. Come to “THINK ABOUT IT”

Let the students work in groups and answer the following questions:

1. Look outside. What’s the weather like today?

2. How does this weather make you feel?

Step3. Listen to the tape and answer the following questions:

1. What’s the weather like today?

2. It is snowing, isn’t it?

3. what’s the temperature?

4. is it going to rain today, isn’t it?

Step4. Read the text and check the answers. Read the text in roles.

Step5. Practice

Work in three students. Suppose you are a weather reporter. Now report today’s weather to the others in your group. Then report it to the class.

Step6. Practice

Make up a dialogue between two or three students in class. It is about the weather in spring. Let some students act it out before the class.

Step7. Homework

1. Find something that represents spring and show it to the class next time.

2. Finish off the activity book.

Lesson 2: It’s Getting Warmer!

Teaching Content:

Mastery words and expressions: become, became, become, fact

Oral words and expressions: daylight, melt, lightning, fascinating

Teaching Aim:

1. Know something more about spring;

2. The compound words.

Teaching Important Points:

1. When does spring begin?

2. How many hours of daylight are there on March 21st?

3. What is the weather like?

Teaching Difficult Points:

the compound words

Teaching Preparation: some pictures of spring

Teaching Aids: audiotape, flashcards, some pictures

Type of lesson: new lesson

Teaching Procedure:

Step1. Let the students on duty reports the weather to the class. The others listen and decide it is right or wrong.

Step2. Listen to the tape and answer the following questions:

1. What’s the date today?

2. How many ways can you write dates?

3. How many hours of daylight are there on March 21st?

4. What is spring weather like?

5. What is the temperature of the air near lighting?

Step3. Read the text and check the answers.

Step4. Listen to the tape again and imitate after it until they can read it fluently and correctly.

Step5. Ask the students to ask other questions according to the text. You can begin like this:

1. When does the sun rise in the morning and when does it set in the evening?

2. Does it snow in early spring?

3. What is sometimes with thunder and lighting?

Step6. Come to “LET’S DO IT”.

Work in groups and discuss these questions. Then let them report it to the class.

Step7. Homework

1. Finish off the activity book.

2. Write a composition about spring.

Summary:

We are enjoying spring now. We can feel it is warmer than before. But not all of us know when the sun rises in the morning and sets in the evening. Let the students observe after class, write it down and report it to the class. It can cultivate the students’ interests of learning English.

Lesson 3: Postcards!

Teaching Content:

Mastery words and expressions: road

Oral words and expressions: outdoors

Teaching Aim:

1. Grasp how to write a letter and the address.

2. Know more about the spring in China and Canada.

Teaching Important Points:

1. Find the differences between China and Canada in spring.

3. Find the differences between the clothes that we wear in winter and in spring.

Teaching Difficult Points:

1. What’s the weather like in Edmonton?

2. How to express one’s idea easily in a letter?

Teaching Preparation: a postcard

Teaching Aids: audiotape, flashcards, postcards

Type of lesson: new lesson

Teaching Procedure:

Step1. Free Talk

Let the students work in three and talk about the sports that we often do in spring. Then give a talk for the class.

Step2. Have a match

Read the text and see who read it best. Remember to encourage the students who preview the new lesson.

Step3. Listen to the tape and read after it. Play the tape for several times until they can read it fluently and correctly.

Step4. Ask the students to find questions and solve them. They can ask the questions like this:

1. How did Li Ming go to school on March twenty-first?

2. What’s the temperature that afternoon?

3. What time does the sun rise this morning?

4. Is it snowing in Canada?

5. When does it often snow in winter?

6. Did Danny fall in the snow?

Step5. Come to “THINK ABOUT IT”

Write a postcard to your friend to introduce the weather here. Then write the address and stick a stamp on it. Mail it in the post office.

Step6. Homework

1. Finish off the activity book.

2. Listen to the song in Lesson 4.

Summary:

Written English is an important part in English learning. Practice is the key to it. Do they have the spelling mistakes or the grammar mistakes in the writing? Find out and help them come over it. Pay more attention to the writing because it’s an important part of communication.

Lesson 4: Sun Is Rising

Teaching Content:

Mastery words and expressions: one by one, change

Oral words and expressions: hillside, gently, blossom

Teaching Aim:

Enjoy the beauty of the spring

Teaching Important Point:

Grasp the changes that spring bring us

Teaching Difficult Points:

How to use “warm” and “gently”.

Teaching Preparation: something that represents spring

Teaching Aids: audiotape, flashcards, pictures or flowers

Type of lesson: new lesson

Teaching Procedure:

Step1. Read the song aloud as a poem. This song has this song has common English words: come with me, through the trees, one by one, the flowers blossom. Translate these expressions into English.

Step2. Play the audiotape and let the students just listen with the eye closed.

Step3. Play the tape again and let the students sing with it.

Step4. Explain the common English expressions.

Step5. Practice the song a few times, with and without the audiotape.

Step6. Come to “LET’S DO IT”.

STEP7. Homework

1. Finish off the activity book.

2. Write down what you can see in spring.

Summary

We use this lesson to cultivate the students’ sense of enjoying English songs. Pay attention to the rhyme, rhythm and repetition in the song. Learning English songs is a little difficult from Chinese songs. Find the ways in which we can learn fast.

Lesson 5: Fun in the Sun

Teaching Content:

Mastery words and expressions: shall, kick

Oral words and expressions: cycling, How/What about…? Shall we…?

Teaching Aims:

How to enjoy oneself in spring.

Teaching Important Points:

1. the sports that we do in spring.

2.some drills: How about…? Let’s…

Teaching Difficult Points:

How to advice sb. to do sth.

Teaching Preparation: basketball and soccer

Teaching Aids: audiotape, flashcards and balls

Type of lesson: new lesson

Teaching Procedure:

Step1. Listen to the tape of Lesson4 again, then let’s sing the song together.

Step2. Listen to the tape and answer the following questions:

1. What’s the degree?

2. What will Danny wear tomorrow?

3. What will they do after school?

4. Why don’t Danny like basketball?

Step3. Read the text and check the answers. Then read the text again.

Step4. Act the dialogue out in front of the class.

Step5. Make up a similar dialogue according to the text. Let’s the students act it out in front of the class.

Step6. Come to “PROJECT”.

Divide the class into several groups. Write the answers down. Ask the several groups to change their answers.

Step7. Homework

1. Finish off the activity book.

2. Review the last lesson.

Summary

Spring is a beautiful season. It’s the favourite season of many people. In this season, everything begins to turn green. Spring represents the beginning. We have many things to do in it. We can fly kites and play ball games. Running in the wind is what we like to do in our childhood. Lead your students to think hard what they like to do in this season. Let them talk freely in the class.

Lesson 6. Danny the babysitter

Teaching Content:

Mastery words and expressions: playground, hold, hold on, come down, push

Oral words and expressions: babysitter, babysit, Debbie, bar, swing, swung

Teaching Aims:

1. We should love each other.

2. The duty of a babysitter

Teaching Important Points:

1.How to demonstrate one thing clearly.

3. Cultivate the spirit of loving each other. Let’s love life and peace.

Teaching Difficult Points:

Some verb phrases: turn around, hold on, fall off, run to, come down, climb on, give sb. a push

Teaching Aids: audiotape, flashcards, pictures

Type of lesson: new lesson

Teaching Procedure:

Step1. Work in pairs. Tell your partner what you did after school yesterday. The teacher walks around to provide help if necessary.

Step2. Skim the text and ask questions by the students themselves. Then solve them by themselves, too. Let some students write their questions on the blackboard. Then let others answer them.

Step3. Listen to the tape and read after it until they can read it correctly and fluently.

Step4. Ask some students to come to the front and act it out. Pay attention to who is clever enough to add something new.

Step5. Retell the story in a third person.

Step6. Come to “THINK ABOUT IT”.

In a group of three, make up a “babysitting” role-play. Ask volunteers to act it out. Then it’s the other students’ turn.

Step7. Homework

1. Finish off the activity book.

2. suppose one day, you become a babysitter, what will you do?

Summary

When we practice in the class, don’t forget to give chances to the poor students. When they have a little progress, encourage them to work hard. That’s what a good teacher should do.

Lesson 7: Danny’s “Debbie” Day

Teaching Content:

Mastery words and expressions: herself

Oral words and expressions: partly, all day

Teaching Aims:

1. Learn to write a diary.

2. What do we write in a diary.

Teaching Important Points:

When we are babysitters, what can we do?

Teaching Difficult Points: the Past Tense

Teaching Preparation: some toys

Teaching Aids: audiotape, flashcards, some toys

Type of lesson: new lesson

Teaching Procedure:

Step1. Work in groups. Retell Lesson 6 in Past Tense in a third person.

Step2. Read the text silently by students themselves. Then answer the questions in the activity. Check the answers in the class.

Step3. Listen to the tape and read after it. Some students may think it is easy to listen with the book. Then listen to the tape again with the book closed. At the same time, the teacher asks some students to repeat some sentences to see if they can listen clearly.

Step4. Let some students read the text aloud in front of the class. Let’s have a match. Who can read it fast and correctly?

Step5. Practice

Work in groups. Write down experience that you have ever been a babysitter. Do you think it easy to be a babysitter? Why or why not?

Step6. Come to “LET’S DO IT”.

Step7. Homework

1. Finish off the activity book.

2. Do the exercises on Page 9.

Summary

Can you write down your experience clearly? We often write in a time order. Expressing your ideas in English is not easy. So give the students more chance to practice. Writing is also an important way to check the grammars.

Lesson 8: Unit Review

Teaching Content:

Mastery words and expressions from Lesson1 to Lesson8.

Oral words and expressions from Lesson1 to Lesson8.

Teaching Aims:

1. Know about more knowledge in spring. There are many things that we don’t know before.

2. What sports do people usually do in China and in Canada?

Teaching Important Points:

1. What’s the weather like in spring?

2. The sports that we do in spring.

Teaching Difficult Points:

The using of some expressions: Let’s…, shall we…?turn around, come down, finally, then

Teaching Preparation: pictures

Teaching Aids: audiotape, flashcards, pictures

Teaching Procedure:

Step1. First let’s sing the song together.

Step2. Talk with your partners about the differences between the sports that we do in China and in Canada.

Step3. Have you ever been a babysitter? Let some students talk about their experience in front of the class.

Step4. Finish the exercises on Page7. Find some difficulties and solve them in front of the class.

Step5.Let some students talk about what we learn in this unit. What do they want to say about spring?

Step6. Homework

1. Finish off the exercises in activity.

2. Prepare for a small quiz.

Summary

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