角与角的大小比较说课稿谢长元

角与角的大小比较说课稿谢长元 湘教版 七年级数学 七年级数学扇形统计图七年级数学上册期末卷七年级数学活动课件七年级数学教学计划七年级数学下册北师大 上册 三年级上册必备古诗语文八年级上册教案下载人教社三年级上册数学 pdf四年级上册口算下载三年级数学教材上册pdf 《角与角的大小比较》说课稿 湖南省怀化市中方县中兴学校 谢长元 各位领导、各位老师大家好: 我说课的题目是《角与角的大小比较》。 《角与角的大小比较》是义务教育课程湘教版七年级数学上册第四章第三节 内容 财务内部控制制度的内容财务内部控制制度的内容人员招聘与配置的内容项目成本控制的内容消防安全演练内容 ，共1个课时，下面我将从六个方面对本节课的设计进行说明。 一、 教材 民兵爆破地雷教材pdf初中剪纸校本课程教材衍纸校本课程教材排球校本教材中国舞蹈家协会第四版四级教材 地位分析: 本节课内容是在学生学习了“线段、射线、直线”、“比较线段的长短”等知识的基础上进行的，它既是对前面所学知识的综合应用，也是对这些知识的拓展与延伸，对学生体会数学建模具有重要的作用，也可以为以后角度的计算和角与角的关系的认识以及平面几何等内容的基础。 二、目标分析 根据数学课程 标准 excel标准偏差excel标准偏差函数exl标准差函数国标检验抽样标准表免费下载红头文件格式标准下载 和本节课教学内容特点，针对学生已有认知水平，我确定本节课的目标如下: (1)、在现实情境中，进一步丰富角、平角、周角及大小的认识; (2)、学会比较角的大小，能用符号语言叙述角的大小关系，解决实际问题; (3)、在操作活动中认识角平分线，能画出一个角的平分线。 (4)、能通过角的测量、折叠等体验数、符号和图形是描述现实世界的重要手段。 (5)、通过实际观察、操作体会角的大小，发展几何直觉。 教学重点:会用不同的方法表示一个角;比较角的大小，认识角的大小关系;认识角的平分 线及画角的平分线。 教学难点:角的表示方法及大小比较 教学方法:直观教学法、发现教学法、主体互动法。 学生学法:让学生动起来，嘴动、眼动、耳动、手动、脑动，充分展现做中学 教学过程: 教学教 师 活 动 学 生 设 计 意 图 环节 活 动 创设1、从火车行驶路线形成角的印象 思考、 挖掘和利用现实生活中与角情 境 2、通过实物或者演示文稿展示各式回答 相关的背景，让学生在现实背 各样的角、生活中的角。 景中认识角( 1、 学生展示: 思考 增强学生的表达能力，让学生 根据导学案展示课前预习成果，尝 回答， 知道本节课的学习内容、学习并归纳本节课知识框架结构 理解 重点。 HGJ222-92 technical specification for welding of aluminium and its alloys 5 low temperature steel welding procedure 6 SH3525-2004 petrochemical JB/ T4708-2000 of welding procedure qualification for steel pressure vessels 7 JB/4709-2000 8 JB4730-2005 pressure vessel welding procedures of steel pressure vessel NDT 9 JB/T4744-2000 steel pressure vessel products mechanical properties test of welded plate II, mechanical equipment installation engineering 1 GB150-98 2 GB50128-2005 vertical cylindrical steel pressure vessel steel welded specification for construction and acceptance of oil tank 3 JB/ T4735-1997 steel welded atmospheric pressure vessel 4 GB50231-2009 mechanical equipment installation engineering construction and acceptance specification for 5 GB50275-98 compressor, fan and pump installation engineering construction and acceptance specification for lifting 6 HG20201-2000 construction installation engineering construction standard 7, HG ... Pressure gauges, using an installed spark arrestor for acetylene cylinders, illegal carrying, using gas cylinders, each operator fined 20 Yuan. Gas bottle without the hot sun exposure measures, responsibilities of team a fine of 50 Yuan. (7) at height and the opening and provisional protective measures have been taken, the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 1~2 million. Direct responsibility for the accident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury 2、学生操作交流: 操作、 锻炼学生的归纳、表达能力， (1)角的相关定义 合作交流 鼓励学生敢于发表自己的观 各小组学生利用课前准备的材料(木 点，通过操作可以让学生直观片，螺丝钉)制作一个角，并展示成 的发现角的大小只与旋转量 果，说明角的形成，通过提问的方式 有关。 引导学生从动态的观点说出角的相 关定义 试 (2)角的表示方法 理解、 通过学生展示、学生补充、教 各小组以抢答的方式回答，教师在黑 记忆 师总结让学生能熟练准确的 板上板示出来，学生适当补充，教师思考、 表示一个角，避免出现表示不 总结说明表示角的时候需要注意的 讨论、 准的现象，突破本节课的重点 地方。 回答 发 (3)角的大小比较 【提问】回忆线段的大小比较方思考、两 法,如何比较角的大小, 位同学操通过学生思考、两位同学操作 学生利用自己制作的角在小组内作解释说解释说明，培养学生的动手操 进行合作交流讨论比较方法，然后让 明 作能力，直观的展示学习成果现 小组选派2名代表上台演示说明角 使学生知道了知识的形成过， 的大小比较方法以及可能出现的情 程，使学生更易接受 况，教师根据学生的操作演示在黑板观察、 上利用教具展示 理解 (4) 角平分线定义 动手操作:(如果有困难可以同桌合操作、 探 作完成) 观察 让学生体验一般与特殊的关在白纸上任意画一个角，标上字母 (如图) 思考、 系，培养学生的逻辑思维能 (1)在? AOB的内部任意画射线 尝试回答 力，逐步锻炼学生的推理能OE，则共有几个角,这些角之间有 怎样的数量关系, 力，进一步巩固对定理的理解 [折一折]:请同学们将手中的角对 及语言的规范，感受成功的喜索 折，你发现了什么, 悦，树立学习数学的信心。 (2)把? AOB折叠，使角的两边OA 和OB重合， HGJ222-92 technical specification for welding of aluminium and its alloys 5 low temperature steel welding procedure 6 SH3525-2004 petrochemical JB/ T4708-2000 of welding procedure qualification for steel pressure vessels 7 JB/4709-2000 8 JB4730-2005 pressure vessel welding procedures of steel pressure vessel NDT 9 JB/T4744-2000 steel pressure vessel products mechanical properties test of welded plate II, mechanical equipment installation engineering 1 GB150-98 2 GB50128-2005 vertical cylindrical steel pressure vessel steel welded specification for construction and acceptance of oil tank 3 JB/ T4735-1997 steel welded atmospheric pressure vessel 4 GB50231-2009 mechanical equipment installation engineering construction and acceptance specification for 5 GB50275-98 compressor, fan and pump installation engineering construction and acceptance specification for lifting 6 HG20201-2000 construction installation engineering construction standard 7, HG ... Pressure gauges, using an installed spark arrestor for acetylene cylinders, illegal carrying, using gas cylinders, each operator fined 20 Yuan. Gas bottle without the hot sun exposure measures, responsibilities of team a fine of 50 Yuan. (7) at height and the opening and provisional protective measures have been taken, the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 1~2 million. Direct responsibility for the accident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury 再把纸铺平，画出折痕OC， ? AOC与?BOC之间有怎样的大小关 系, 新 【大屏幕】规范由定义的推导过程。 如图所示: (1)?射线OC是?AOB的平分线， ??AOC=?BOC= 或?AOB=2? =2 ? , 知 (2)??AOC=?BOC= 或?AOB=2? =2? ?射线OC是?AOB的平分线， 例 【大屏幕】附录1 要求学生会用上述学习的知题 思考 识点通过小组交流解决各个示 问题 范 巩 【大屏幕】巩固练习(见附录2) 积极思循序渐进提高难度、提高灵活固 考、展开运用知识的能力 练 讨论、踊 习 跃回答 拓 【大屏幕】探究题(见附录3) 猜测、讨 展 【备注】如果时间不允许的话，论，寻找使学生的思路进一步得以拓思 该题可作为课后作业，并给予简单的规律 宽，使学生能力得以提高。 路 提示。 HGJ222-92 technical specification for welding of aluminium and its alloys 5 low temperature steel welding procedure 6 SH3525-2004 petrochemical JB/ T4708-2000 of welding procedure qualification for steel pressure vessels 7 JB/4709-2000 8 JB4730-2005 pressure vessel welding procedures of steel pressure vessel NDT 9 JB/T4744-2000 steel pressure vessel products mechanical properties test of welded plate II, mechanical equipment installation engineering 1 GB150-98 2 GB50128-2005 vertical cylindrical steel pressure vessel steel welded specification for construction and acceptance of oil tank 3 JB/ T4735-1997 steel welded atmospheric pressure vessel 4 GB50231-2009 mechanical equipment installation engineering construction and acceptance specification for 5 GB50275-98 compressor, fan and pump installation engineering construction and acceptance specification for lifting 6 HG20201-2000 construction installation engineering construction standard 7, HG ... Pressure gauges, using an installed spark arrestor for acetylene cylinders, illegal carrying, using gas cylinders, each operator fined 20 Yuan. Gas bottle without the hot sun exposure measures, responsibilities of team a fine of 50 Yuan. (7) at height and the opening and provisional protective measures have been taken, the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 1~2 million. Direct responsibility for the accident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury 课堂 【提问】本节课我们学习了哪些回顾、归 小结 定理?在表述这些定理时，应注意什纳 将本节课知识进行回顾。 么呢, 布置 【大屏幕】布置作业: 课后完成 课后能进一步巩固，鼓励学生 作业 去发现身边的数学问题。 附录1: 例1 判断下列语句是否正确 (1)两条射线组成的图形叫做角 (2)延长角的两边 (3)角的大小与两边的长短无关 (4)角的两边是射线，所以角不可度量 (5)平角是一条直线 (6)周角是一条射线 例2把图中的角表示成下列形式,哪些是正确?哪些不正确?对的打?,错的打×. (1) ? APO ( ) (2)?AOP ( ) (3) ? OPC ( )(4?OCP ( ) (5) ? O ( ) (6)?P ( ) 例3对于如图所示的各个角，用 “>”、“<” 或“=” 填空: ?AOB ?AOC，?DOB ?BOC， ?BOC ?AOD，?AOD ?BOD. 例4 练习:已知 OB是?AOC的平分线，OD是?COE平 分线。 (1)如果?AOB,40度，?DOE,30度,那么?BOD是多少度, (2)如果?AOE,140度，?COD,30度,那么?AOB是多少度, HGJ222-92 technical specification for welding of aluminium and its alloys 5 low temperature steel welding procedure 6 SH3525-2004 petrochemical JB/ T4708-2000 of welding procedure qualification for steel pressure vessels 7 JB/4709-2000 8 JB4730-2005 pressure vessel welding procedures of steel pressure vessel NDT 9 JB/T4744-2000 steel pressure vessel products mechanical properties test of welded plate II, mechanical equipment installation engineering 1 GB150-98 2 GB50128-2005 vertical cylindrical steel pressure vessel steel welded specification for construction and acceptance of oil tank 3 JB/ T4735-1997 steel welded atmospheric pressure vessel 4 GB50231-2009 mechanical equipment installation engineering construction and acceptance specification for 5 GB50275-98 compressor, fan and pump installation engineering construction and acceptance specification for lifting 6 HG20201-2000 construction installation engineering construction standard 7, HG ... Pressure gauges, using an installed spark arrestor for acetylene cylinders, illegal carrying, using gas cylinders, each operator fined 20 Yuan. Gas bottle without the hot sun exposure measures, responsibilities of team a fine of 50 Yuan. (7) at height and the opening and provisional protective measures have been taken, the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 1~2 million. Direct responsibility for the accident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury 巩固练习: 附录2: 一、填空: 1、右图中有哪几个角,用适当的方式将这些角表示出来( ，ABC2、下面表示的图是 ( ) CBC A ABCABA (A) (B) (C) (D) 3、下列4个图形中,能用?1,?AOB,?O三种方法表示同一角的图形是( ) CDABA1BO11OOAOBABCABDB 4、图中,小于平角的角有( ) AC A.5个 B.6个 C.7个 D.8个 D 5、下列两条射线能正确表示一个角的是( ) A B C D 6、下列说法中不正确的是 ( ) A.?AOB的顶点是O点 B.射线BO，射线AO分别是?AOB的两条边 C.?AOB的边是两条射线 D.?AOB与?BOA表示同一个角 7.下列说法错误的是( ) A.角的大小与角的边画出部分的长短没有关系; B.角的大小与它们的度数大小是一致的; C.角的和差倍分的度数等于它们的度数的和差倍分;D.若?A+?B>?C,那么?A一定大于?C。 8、把上图中?AOD，?AOB，?AOC，从大到小排列. C BD A O HGJ222-92 technical specification for welding of aluminium and its alloys 5 low temperature steel welding procedure 6 SH3525-2004 petrochemical JB/ T4708-2000 of welding procedure qualification for steel pressure vessels 7 JB/4709-2000 8 JB4730-2005 pressure vessel welding procedures of steel pressure vessel NDT 9 JB/T4744-2000 steel pressure vessel products mechanical properties test of welded plate II, mechanical equipment installation engineering 1 GB150-98 2 GB50128-2005 vertical cylindrical steel pressure vessel steel welded specification for construction and acceptance of oil tank 3 JB/ T4735-1997 steel welded atmospheric pressure vessel 4 GB50231-2009 mechanical equipment installation engineering construction and acceptance specification for 5 GB50275-98 compressor, fan and pump installation engineering construction and acceptance specification for lifting 6 HG20201-2000 construction installation engineering construction standard 7, HG ... Pressure gauges, using an installed spark arrestor for acetylene cylinders, illegal carrying, using gas cylinders, each operator fined 20 Yuan. Gas bottle without the hot sun exposure measures, responsibilities of team a fine of 50 Yuan. (7) at height and the opening and provisional protective measures have been taken, the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 1~2 million. Direct responsibility for the accident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury 【能力提升】 9、已知如右图 (1)试用三个大写字母表示:?1就是 ， ?2就是 ，?3就是 ，?4就是 。 2)图中共有 个角(除去平角)，其中可以用一个大写字母表示的角有 个. ( 10、 请将图中的角用不同方法表示出来，并填写下表: ?ABE ?1 ?2 ?3 附录3:探究题: 1.如图,把?AOB绕着O点按逆时针方向旋转一个角度, 得?A′OB′,指出图中所有相等的角,并简要说明理由. 2.如图,?AOB是平角,OD、OC、OE是三条射线,OD是?AOC的平分线, 请你补充一个条件,使?DOE=90?,并说明你的理由. HGJ222-92 technical specification for welding of aluminium and its alloys 5 low temperature steel welding procedure 6 SH3525-2004 petrochemical JB/ T4708-2000 of welding procedure qualification for steel pressure vessels 7 JB/4709-2000 8 JB4730-2005 pressure vessel welding procedures of steel pressure vessel NDT 9 JB/T4744-2000 steel pressure vessel products mechanical properties test of welded plate II, mechanical equipment installation engineering 1 GB150-98 2 GB50128-2005 vertical cylindrical steel pressure vessel steel welded specification for construction and acceptance of oil tank 3 JB/ T4735-1997 steel welded atmospheric pressure vessel 4 GB50231-2009 mechanical equipment installation engineering construction and acceptance specification for 5 GB50275-98 compressor, fan and pump installation engineering construction and acceptance specification for lifting 6 HG20201-2000 construction installation engineering construction standard 7, HG ... Pressure gauges, using an installed spark arrestor for acetylene cylinders, illegal carrying, using gas cylinders, each operator fined 20 Yuan. Gas bottle without the hot sun exposure measures, responsibilities of team a fine of 50 Yuan. (7) at height and the opening and provisional protective measures have been taken, the responsible unit fined 200 Yuan, construction person in charge a fine of 50 Yuan. (8) no permit to work and the job in accordance with the provisions, on the job unit fined 300 yuan, the unit will charge a fine of 100 Yuan. 7.5.3 accident penalties (1) injuries fatalities directly punished 1~2 million. Direct responsibility for the accident and have the corresponding responsibility of leadership, such as concerning administrative sanctions, should be brought to the company or the relevant Department. (2) personal injury