长方形面积公式的推导

长方形面积 公式 小学单位换算公式大全免费下载公式下载行测公式大全下载excel公式下载逻辑回归公式下载 的推导 汇总诸多的教学设计基本为: 第一层引导学生通过动手测量，初步感悟每排摆的面 积单位数与长、摆的排 数与宽之间的内在联 系。 4×3=12(平方分米) 这个长方形的面积是12平方分米。 第二层通过分组探究，推导出长方形的面积公式。每组同学准备12个1平方分米的面积单位，要求选择其中若干面积单位拼成长方形，并把结果填写在表格里。 and approval personnel shall be strictly guided by credit policies and requirements for review and approval. Review approval through logical examination, comparison and verification of personnel as well as their own experience in review and approval to enhance the authenticity of the credit information audit. For obvious errors, contradictions, or unreasonable or unexplainable data, information should be indicated in the review approval. Content review and approval personnel should conduct a 长 宽 长方形的面积 6 2 12 4 3 12 2 4 8 3 3 9 观察长方形的面积与长和宽有什么关系,学生们自然得出长方形的面积=长×宽。 这样的教学设计，虽然为学生创设出合作探究的发展空间，但学生对“长与宽都是线段，以长度为单位，它们的乘积为什么就是面积,为什么长方形的长是几，每排就能摆几个这样的面积单位，长方形的宽是几，就能摆这样的几排”等核心问题还是迷惑不解，而这些问题恰恰就是教学and approval personnel shall be strictly guided by credit policies and requirements for review and approval. Review approval through logical examination, comparison and verification of personnel as well as their own experience in review and approval to enhance the authenticity of the credit information audit. For obvious errors, contradictions, or unreasonable or unexplainable data, information should be indicated in the review approval. Content review and approval personnel should conduct a 的关键。 我们知道，有关平面图形的知识(平面图形面积公式的推导、面积单位之间的换算等)，它们的核心概念是面积单位。我们要以基本概念“面积单位”为核心，抓住每排摆的面积单位数、摆的排数和长方形的长、宽之间的内在联系进行推导。教学过程不但要帮助学生储备知识，更要注重学生思维能力的培养。任何忽视探究知识内涵的教学，都只能使学生获得肤浅的、缺乏生命活力的知识。 第一层深化理解“面积单位”。利用多媒体课件，演示由线段围成正方形，进而形成“面”的演变过程，and approval personnel shall be strictly guided by credit policies and requirements for review and approval. Review approval through logical examination, comparison and verification of personnel as well as their own experience in review and approval to enhance the authenticity of the credit information audit. For obvious errors, contradictions, or unreasonable or unexplainable data, information should be indicated in the review approval. Content review and approval personnel should conduct a 使学生形成清晰的表象，有利于学生对“面积单位”概念的深化理解。随之询问，面积单位是如何规定的以及逆向角度的设问，不仅让学生明确面积是1平方厘米的正方形，它们的边长必定是1厘米，而且还要让学生明确，边长1厘米的正方形，它的面积必定是1平方厘米。因为它是推导长方形面积公式的知识核心。 第二层是以“面积单位”概念为核心推导长方形的面积。教学时要根据学生的认知规律为核心提供丰富的感性材料，引导学生通过亲自动手测量的活动方式，调动学生的多种感官参与到形成数学概念的思维过程and approval personnel shall be strictly guided by credit policies and requirements for review and approval. Review approval through logical examination, comparison and verification of personnel as well as their own experience in review and approval to enhance the authenticity of the credit information audit. For obvious errors, contradictions, or unreasonable or unexplainable data, information should be indicated in the review approval. Content review and approval personnel should conduct a 中来。心理学家皮亚杰也指出:“活动是认识的基础，智慧从动作开始，”动作与动脑是相互促进的。我们先让学生亲自动手用合适的面积单位去测量，分别沿长和宽摆，学生初步感悟每排摆的面积单位数排数就是这， 个长方形的面积。但同学们对长方形的面积为什么是长宽还是迷惑不解。， 教师再引导学生去推导，(1)顺向思维:出示长方形，首先根据这个长方形的大小判定用哪个面积单位去测量，再利用多媒体课件展示摆的过程，沿着长正好摆4个这样的面积单位，那这个长方形的长必定是多少,引发学生思考——知道面积单位是1and approval personnel shall be strictly guided by credit policies and requirements for review and approval. Review approval through logical examination, comparison and verification of personnel as well as their own experience in review and approval to enhance the authenticity of the credit information audit. For obvious errors, contradictions, or unreasonable or unexplainable data, information should be indicated in the review approval. Content review and approval personnel should conduct a 平方分米，它的边长必定是1分米，摆1个这样的面积单位，它的边长就是1分米，沿着长摆了4个这样的面积单位，就有4个1分米，所以这个长方形的长必定是4分米。同样道理，沿着宽摆3个这样的面积单位，这个长方形的宽必定是3分米。(2)逆向思维:出示一个长4分米、宽3分米的长方形，研究长、宽与面积之间的关系。知道长是4分米，根据前面的研究，你立刻就能推导出什么,——用1平方分米的面积单位去测量，那它的边长必定是1分米。那有1分米就能摆1个这样的面积单位。长是4分米，那沿着长必定能摆4个这样的and approval personnel shall be strictly guided by credit policies and requirements for review and approval. Review approval through logical examination, comparison and verification of personnel as well as their own experience in review and approval to enhance the authenticity of the credit information audit. For obvious errors, contradictions, or unreasonable or unexplainable data, information should be indicated in the review approval. Content review and approval personnel should conduct a 面积单位.。宽是3分米，那沿着宽必定能摆3个这样的面积单位，即3排。所以这个长方形的面积是12平方分米。 通过严密的逻辑推理，同学们欣喜地发现:长方形的长是几，每排必定摆几个这样的面积单位;长方形的宽是几，就能摆这样的几徘。当学生对概念形成初步认识后，我们没有让学生的思维停留在相对较低的思维水平，而是通过有效的训练，使学生对概念的认识逐步加深，进而把其他数学知识围绕着这个最基本的概念形成层次化、网络化的知识结构。先给学生出示这样一道应用题:给一间and approval personnel shall be strictly guided by credit policies and requirements for review and approval. Review approval through logical examination, comparison and verification of personnel as well as their own experience in review and approval to enhance the authenticity of the credit information audit. For obvious errors, contradictions, or unreasonable or unexplainable data, information should be indicated in the review approval. Content review and approval personnel should conduct a 长8米、宽6米的教室铺地砖，求教室的面积。学生的描述相当形象:“我的眼前出现一间教室，我们正在用面积为1平方米的方砖为教室铺地，这间教室长8米，每排就能铺8个1平方米，这间教室宽6米，就能铺这样的6排，所以这间教室的面积是48平方米。”语言是逻辑思维的外壳，我们可以通过学生语言的表述透视出其思维的发展。他们不仅建立起清晰的概念，也从根本上打破对长与宽相乘为何就成为面积的疑惑，从而理解到长方形的面积=长×宽的真正内涵，即所谓不仅知其然，而且知其所以然。这也为五 年级 六年级体育公开课教案九年级家长会课件PPT下载六年级家长会PPT课件一年级上册汉语拼音练习题六年级上册道德与法治课件 学生学习长方体and approval personnel shall be strictly guided by credit policies and requirements for review and approval. Review approval through logical examination, comparison and verification of personnel as well as their own experience in review and approval to enhance the authenticity of the credit information audit. For obvious errors, contradictions, or unreasonable or unexplainable data, information should be indicated in the review approval. Content review and approval personnel should conduct a 的体积推导打下坚实的知识基础和思维条件。为什么长×宽×高的积就是这个长方体的体积,学生自然会描绘出，长方体的长是几，每排必定能摆几个这样的体积单位;长方体的宽是几，就能摆这样的几排;这样就形成1层，长方体的高是几，必定就能摆这样的几层。 这样的教学设计，始终以最原始的概念为魂，以知识间的内在联系为线，既注重知识的发现过程，又重视结论的推导过程，同时培养学生的 分析 定性数据统计分析pdf销售业绩分析模板建筑结构震害分析销售进度分析表京东商城竞争战略分析 推理能力和主动探索的精神。学生在教师精心创设的问题情境中，去观察、去发现、去探索，从而获得新认and approval personnel shall be strictly guided by credit policies and requirements for review and approval. Review approval through logical examination, comparison and verification of personnel as well as their own experience in review and approval to enhance the authenticity of the credit information audit. For obvious errors, contradictions, or unreasonable or unexplainable data, information should be indicated in the review approval. Content review and approval personnel should conduct a 识、新理解。我们也会切切实实感到 抓知识结构所体现出的思维价值和 它的活力。 and approval personnel shall be strictly guided by credit policies and requirements for review and approval. Review approval through logical examination, comparison and verification of personnel as well as their own experience in review and approval to enhance the authenticity of the credit information audit. For obvious errors, contradictions, or unreasonable or unexplainable data, information should be indicated in the review approval. Content review and approval personnel should conduct a