2021年人教版五年级数学上册第五单元简易方程教案.pdf

单元教案1.使学生初步认识用字母表示数的意义和作用,能够用字母表示学过的运算定律和计算公式,能够在具体情境中用字母表示常见的数量关系;初步学会根据字母所取的值,求含有字母的式子的值。2.使学生初步了解方程的意义,初步理解等式的基本性质,能用等式的性质解简易方程。3.使学生感受数学与现实生活的联系,初步学会列方程解决一些简单的实际问题;培养学生根据具体情况,灵活选择算法的意识和能力。1.关注由具体到一般的抽象概括过程。本单元的知识大多比较抽象,教学时要充分利用学生原有的相关认识,关注由具体实例到一般意义的抽象概括过程。学习用字母表示数量关系、方程的概念或等式的性质时,既要发挥具体实例对于抽象概括的支撑作用,又要及时引导学生超脱实例的具体性,进行必要的抽象概括。2.用好教材资源,适当扩展联系实际的范围。在本单元中,用字母表示数量关系和列方程解决实际问题,都是把所学知识运用于实际生活中。教材从小学高年级学生的共性着眼,精心筛选,设计了不少生动而富有意义的现实题材,如人在地球上与月球上的举重质量的关系,标准体重与身高的关系。教学时,应用好教材提供的资源,从本地、本校的特色出发,适当补充一些学生身边的题材,以进一步激发学生的学习热情,培养学生的数学应用意识。3.重视良好学习习惯的培养。在本单元的教材中,应注意、培养学生规范书写和自觉检验的习惯。就书写习惯来说,无论是含有字母式子的书写,还是解方程的书写,都要从一开始就强化书写规范,以发挥首次感知、先入为主的强势效应,形成良好的书写习惯。从解数学题的检验来看,解方程的检验,方法易学,操作简便,而且最容易显示检验的效果,因而是培养学生检验习惯的一个重要契机,应引起教师的重视,并加以把握。1用字母表示数.6课时2解简易方程.7课时整理和复习.2课时精品w o r d 可编辑资料-第 1 页，共 49 页-用含有字母的式子表示数量关系。(教材第 5 2 5 3 页)1.使学生在理解数量关系的基础上,会用含有字母的式子表示数量关系。2.使学生在理解含有字母式子的具体意义的基础上,会根据字母的取值,求含有字母的式子的值。3.培养学生的抽象思维能力和归纳概括能力。重点:会用含有字母的式子表示数量关系。难点:理解用含有字母的式子表示数量关系的意义。投影片。1.在下面的里填上适当的名称。投影出示练习。时间=路程单产量=总产量工作效率 时间=总价2.引入。师:你们的数学课本是多少元?买一本数学课本和一本数学课外读物一共要多少元?学生一定会问数学课外读物的价钱是多少,这时教师指出:既然不知道数学课外读物的价钱,能否用一个字母表示?现在谁能说出买一本数学课本和一本数学课外读物一共要多少元?请学生回答:4.8 7+x表示的是什么?师:这个含有字母的式子也能表示数量关系,今天我们就来探讨这个问题。板书课题:用含有字母的式子表示数量关系1.指名学生说出自己的年龄。李铭同学报出自己1 1岁。师:老师比李铭大2 5岁。老师的年龄是多少?请你算一算李铭在1岁、2岁、3岁到现在 1 1岁时,老师各是多少岁。教师板书如下:李铭的年龄老师的年龄11+2 5=2 622+2 5=2 733+2 5=2 844+2 5=2 9精品w o r d 可编辑资料-第 2 页，共 49 页-文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3提问:求老师年龄的问题提完了吗?(没有)为什么?(因为李铭在不断地长大,李铭的岁数每增加一岁,老师的岁数也增加一岁)上面这些算式表示什么意思?上面这些算式表示,当李铭 1岁时,老师(1+2 5)岁;当李铭 2岁时,老师(2+2 5)岁当李铭1 1岁时,老师(1 1+2 5)岁 虽然李铭和老师的年龄都在变,但是什么没有变?(老师比李铭大2 5岁)我们已经学习了用字母表示数,能不能用一个简明的式子表示老师的年龄呢?用字母 a表示李铭的年龄,那么老师的年龄就是a+2 5。(用其他字母表示也可以)教师继续板书:a与 a+2 5从 a+2 5这个式子里,你们知道些什么信息?学生同桌议论或小组讨论,然后交流汇报。a+2 5既表明了老师的年龄,又表明了老师比李铭大 2 5岁,所以,我们只要知道李铭的年龄a,就能用这个数量关系算出老师的年龄。师:对,只要知道了李铭的年龄,就可以求出老师的年龄。我们可以计算一下;当李铭 1 2岁小学毕业时,老师多大?学生回答,教师板书:当 a=1 2 时,a+2 5=1 2+2 5=3 7。师:当李铭 1 9岁考入大学时,老师多大?学生回答,教师板书:当 a=1 9 时,a+2 5=1 9+2 5=4 4。思考:我们学习了用含有字母的式子表示数量关系,它有什么优点?学生通过讨论,认识到用字母可以表示数量之间的关系。出示教材第5 2页例 1:(1)学生默读题,理解题意。(2)学生用自己的语言叙述题意。(3)学生自主解决。(4)学生集体交流、订正。2.教学教材第5 3页例 2。投影出示:在月球上,人能举起物体的质量是地球上的6倍。(1)读题,引导学生按下面的过程自己推算,并填写下表。在地球上能举起物体的质量/k g 在月球上能举起物体的质量/k g11 6=622 6=1 233 6=1 8(2)提问。师:假如用字母x表示人在地球上能举起物体的质量,你能用含有字母的式子表示出人在月球上能举起的质量吗?(3)算一算:教材插图中的小朋友在月球上能举起的质量是多少?学生计算后交流,教师板书:6 x=6 1 5=9 0(k g)(4)说一说例2 中的字母分别可以表示哪些数。注意:人的寿命是有限的,能举起的质量也是有限的,因此 a、x表示的数也是有限的。精品w o r d 可编辑资料-第 3 页，共 49 页-文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S31.列式计算。停车场有m 辆车,开走 8 辆。(1)当 m=2 4时,还剩多少辆?(2)当 m=3 2时,还剩多少辆?2.想一想,填一填。当 x=()时,8 x=1;当 x=()时,8 x=8;当 x 8;当 x ()时,8 x 3以后,两者的值差,越来越大,不可能相等。学生独立完成,集体订正。当 x=6时,x2=3 6,2 x=1 2;当 x=0或 x=2时,x2和 2 x正好相等。1.填空。(1)每袋面粉重a千克,每袋大米重b千克,8袋面粉和5袋大米共重()千克。(2)5 x+4 x=()8 y-y=()7 x+7 x+6 x=()7 a a=()1 5 x+6 x=()5 b+4 b-9 b=()2.选择。(将正确答案的序号填在括号里)(1)a2与()相等。A.a 2B.a+2C.a aD.a-2 (2)2 x一定()x。A.大于B.小于C.等于D.不能确定 (3)当 a=5,b=4时,a b+3的值是()。A.5+4+3=1 2B.5 4+3=5 7C.5 4+3=2 33.(1)(2)4.实验小学举行了植树活动,四年级一班计划植树8 0棵。(1)如果平均每天栽a棵树,栽了 5 天,还剩多少棵树没栽?(2)当 a=1 2时,还剩多少棵树没栽?5.如图,小萍和小明同时从家里去栈桥,6分钟后在栈桥相遇。(1)用含有字母的式子表示小萍和小明家相距多远。(2)当 a=6 5、b=7 5 时,小萍和小明家相距多少米?6.东苑小区有柳树x棵,杨树比柳树的2 倍少 1 8棵。(1)用含有字母的式子表示出杨树和柳树的总棵数。(2)当 x=1 2 0时,求杨树和柳树的总棵数。精品w o r d 可编辑资料-第 19 页，共 49 页-文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3下图是亮亮用火柴棒围成的6个正六边形组成的花边图案。(1)按如图方式,围 5个正六边形要()根火柴。(2)围 1 0 0 个正六边形要()根火柴。(3)围 m 个正六边形需要火柴()根。还有其他算法吗?课堂作业新设计1.(1)8 a+5 b(2)9 x7 y2 0 x7 a22 1 x02.(1)C(2)D(3)C3.(1)m-3 n5 y4.(1)8 0-5 a(2)2 05.(1)6 a+6 b 或 6(a+b)(2)8 4 06.(1)2 x-1 8(2)2 2 2思维训练(1)2 2(2)4 0 2(3)4 m+2其他算法略。教材习题练习十三1.(1)中午的温度(2)男生的人数(3)3 分球的得分2.(1)3+t(2)2 0-a(3)2 x(4)b 1 2(5)5 a-4.8(6)x-93.略4.(1)9.1(2)8 4(3)85.(1)5 x+3(2)1 36.(1)1 3 51 3 5 x(2)4 0 5 07.8 a2 x7 y8 b8.(1)a-8 b(2)3 89.(1)3 6 t3 6 0 k m(2)(6 4 8-3 6 t)k m2 1 6 k m10*.(1)3 n+1(2)6 411*.当 x=6时x2=3 62 x=1 2当 x=0或 x=2时,x2=2 x方程的意义和等式的性质。(教材第 6 2 6 6页)1.使学生理解和掌握方程的意义和等式的性质。2.提高学生观察、归纳和概括的能力。3.培养学生仔细观察的良好习惯。重点:理解方程的意义。精品w o r d 可编辑资料-第 20 页，共 49 页-文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3难点:掌握等式的性质。实物投影,自制天平教具。在下面算式的里填上“”“2 0 0。(4)再增加 1 0 0克砝码,天平往砝码这边倾斜。提问:哪边重些?怎样用式子表示?(学生口答)板书:1 0 0+x 3 0 0(5)把一个 1 0 0克砝码换成5 0克的,天平重新平衡。提问:现在两边的质量怎样了?用式子怎样表示?(学生口答)板书:1 0 0+x=2 5 0教师建议:像这样的含有未知数的等式,你们知道它的名字吗?(板书课题:方程的意义)3.学生试着写出一个方程,互相交流。提问:判断一个式子是不是方程的条件是什么?小结:一看是不是等式,二看有没有未知数。4.完成教材第6 3页“做一做”的第1题。交流时说明“是方程”或“不是方程”的理由。5.学生自己看课后阅读材料。6.教学等式的性质。(1)师:你们用天平做过游戏吗?大家一起来做一个游戏。精品w o r d 可编辑资料-第 21 页，共 49 页-文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3(2)教师演示。天平左边放上茶壶,右边放上两个茶杯,保持平衡。提问:怎样变换,能使天平仍然保持平衡?往两边各放1个同样的茶杯,天平会发生什么变化?(学生回答后,教师演示验证)如果两边各放上2 个茶杯,天平还保持平衡吗?两边各放上同样的1把茶壶呢?(学生回答后,教师再演示)指出:如果设 1把茶壶重 a克,1 个茶杯重b克,则上面的过程可以怎样表示?(学生回答,教师板书)a=2 ba+b=2 b+ba+2 b=2 b+2 ba+a=2 b+a提问:你能用自己的语言概括上面的规律吗?小结:等式两边同时加上或减去同一个数,左右两边仍然相等。(3)对于第二幅图,也可以采用上面的方法进行演示并提问。提问:你能把两个实验的结论归纳为一句话吗?(4)对于第三、第四幅图,也这样操作,归纳结论。1.在等式后面的括号里画“”。(1)2.6 4=1 0.4()(2)4.7-2.0 1 3()(3)3 x 7()(2)3 x-2=4.4()(3)1.2+3.5-4=0.7()(4)x+8=9 2()(5)4.5 x-2.6()(6)x-2.9=0()3.求下面加法竖式中的字母a,b,c,s各代表什么数。4.根据下面的等式,求出 a,b,c各代表什么数。a+b+c=3 3a+a+b=3 1a+b-c=9精品w o r d 可编辑资料-第 22 页，共 49 页-文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I6S3文档编码:CT7A5P7I10R3 HI4Z2J1M6M7 ZG5O6S2I