最新人教版小学数学二年级上册说课稿+轴对称图形优秀名师资料.docx

1、最新人教版小学数学二年级上册说课稿+轴对称图形优秀名师资料人教版小学数学二年级上册说课稿 轴对称图形教学内容:义务教育课程标准实验教科书第5661页，轴对称图形 教学目标: 1、联系生活中的具体物体，通过观察和动手操作，使学生初步体会生活中的对称现象，认识轴对称图形。 2、使学生能根据轴对称图形的初步认识，在实物图案和平面图形中识别轴对称图形，能用一些方法做出轴对称图形，能在方格纸上画出简单的轴对称图形。 3、使学生在认识和制作简单的轴对称图形的过程中，感受到物体或图形的对称美。激发数学学习的兴趣。 教学重点: 轴对称图形的初步认识和制作。 教学难点: 轴对称图形的初步认识。 教学准备:多媒体

2、课件、实物投影仪、剪刀、彩纸、图形纸、钉子板、字母卡片等。 教学过程 一、猜一猜情景导入 1:欣赏录像。(课件出示春天到北京旅游的景象) 二、观察、操作探究特征 1、观察，初步感知 (1)认识对称 summer of masonry construction, brick requires sufficient moist. 8.6.2.6 you must take the following measures to concrete construction in summer high temperature impact on concrete a. hardening speed u

3、p, vibrating difficulties reduced bleeding, fast drying, easy to crack (plastic), high early strength, fast early hydration heat, less cooling, temperature increases rapidly, due to temperature difference cracks. B. pouring daytime high temperatures, due to the high temperature effect of concrete st

4、rength, stability, in varying degrees, on mixing processes, perfusion vibration and moisture conservation, effective measures should be taken. 2) main measures taken by a. temperature control the water temperature in your standard mix proportion of concrete 2 degrees, the concrete temperature 0.5 de

5、grees. B. with the controlled addition of retarder agent can reduce the effects of concrete under high temperature, but make some performance degradation of concrete, so when you are using additives must be implemented upon approval by the supervising engineer. C. time control suitable for work at n

6、ight, should seek to reduce the mixing time and shipping time at high temperatures. D. strengthen the conservation and high temperatures after pouring in the early days of continuous water conservation to prevent surface drying and covering thin-film wet grass bag to make it moist State in 24 hours.

7、 8.6.3 8.6.3.1 winter construction measures in winter construction preparation 1) required winter construction materials, equipment, planning ahead of time comes into 观察照片，你能发现它们有什么特点吗,(师课件点击放大剪纸图。) 生:它的两边都是一模一样的。 (课件点击返回)那其它物体有没有两边也是一模一样的呢, (2)揭示对称 像这样物体的两边是一模一样的，我们就说这个物体它是对称的。那这些物体它们都是对称的。 (3)扩展认识

8、 在生活中你还见过哪些物体也是对称的呢,(课件出示)和你的同桌说一说。 (同桌之间自由说，全班交流) 2、操作，体会特征 (1)从物体到图形的认识 把这些对称的物体画下来，得到下面的图形:(电脑出示按天安门、飞机、奖杯、蝴蝶等实物画下来的图形) 继续观察，这几个图形有什么特点呢, 任选一个图形，在小组内合作，尝试能用什么方法来验证它 们是对称的呢, (学生操作，教师巡视，选择不同的实验方法。) 交流反馈。演示折纸过程:对折后两边是对称的 板贴:对折 summer of masonry construction, brick requires sufficient moist. 8.6.2.6

9、you must take the following measures to concrete construction in summer high temperature impact on concrete a. hardening speed up, vibrating difficulties reduced bleeding, fast drying, easy to crack (plastic), high early strength, fast early hydration heat, less cooling, temperature increases rapidl

10、y, due to temperature difference cracks. B. pouring daytime high temperatures, due to the high temperature effect of concrete strength, stability, in varying degrees, on mixing processes, perfusion vibration and moisture conservation, effective measures should be taken. 2) main measures taken by a.

11、temperature control the water temperature in your standard mix proportion of concrete 2 degrees, the concrete temperature 0.5 degrees. B. with the controlled addition of retarder agent can reduce the effects of concrete under high temperature, but make some performance degradation of concrete, so wh

12、en you are using additives must be implemented upon approval by the supervising engineer. C. time control suitable for work at night, should seek to reduce the mixing time and shipping time at high temperatures. D. strengthen the conservation and high temperatures after pouring in the early days of

13、continuous water conservation to prevent surface drying and covering thin-film wet grass bag to make it moist State in 24 hours. 8.6.3 8.6.3.1 winter construction measures in winter construction preparation 1) required winter construction materials, equipment, planning ahead of time comes into 师:那再请

14、同学们观察一下，你把图形对折后发现了什么呢,在小组里说一说。(学生小组交流) 生:它们对折后两边是对称(一模一样)的。 师:那其他图形也是这样的吗,师加以补充:像这样，对折后折痕两边的部分完全一样(对称)，称为完全重合。板贴:完全重合 师:为了使大家看得更清楚，我们请电脑老师来演示一下。(电脑演示:2个对折完全重合的过程)。请大家把其余的两个图形再折一折，你发现了什么,(学生操作，小组交流述说) 师:这些图形它们有什么共同的特征呢,(点名回答) 生:它们对折后两边是能完全重合的。 小结:像这样，对折后两边能完全重合的图形是轴对称图形(板帖:轴对称图形的概念) 师:今天我们就要来学习轴对称图形(

15、板贴课题:轴对称图形) 师:这些图形都是(学生讲轴对称图形)，那谁来说说这三张图形为什么是轴对称图形呢, 生:(点名回答)它们对折后能完全重合，所以是轴对称图形。 师:如果把刚才对折后的图形打开来看看，还发现什么呀, 生:一条折痕。 师:有一条折痕。这条折痕就是这个图形的对称轴。(电脑演示对称轴)(板贴:对称轴) 师:你能找出另外两张图形中的对称轴吗,相互说一说。(同桌交流) summer of masonry construction, brick requires sufficient moist. 8.6.2.6 you must take the following measures

16、to concrete construction in summer high temperature impact on concrete a. hardening speed up, vibrating difficulties reduced bleeding, fast drying, easy to crack (plastic), high early strength, fast early hydration heat, less cooling, temperature increases rapidly, due to temperature difference crac

17、ks. B. pouring daytime high temperatures, due to the high temperature effect of concrete strength, stability, in varying degrees, on mixing processes, perfusion vibration and moisture conservation, effective measures should be taken. 2) main measures taken by a. temperature control the water tempera

18、ture in your standard mix proportion of concrete 2 degrees, the concrete temperature 0.5 degrees. B. with the controlled addition of retarder agent can reduce the effects of concrete under high temperature, but make some performance degradation of concrete, so when you are using additives must be im

19、plemented upon approval by the supervising engineer. C. time control suitable for work at night, should seek to reduce the mixing time and shipping time at high temperatures. D. strengthen the conservation and high temperatures after pouring in the early days of continuous water conservation to prev

20、ent surface drying and covering thin-film wet grass bag to make it moist State in 24 hours. 8.6.3 8.6.3.1 winter construction measures in winter construction preparation 1) required winter construction materials, equipment, planning ahead of time comes into 师:(小结)现在同学们知道什么图形才是轴对称图形吗,在小组里交流一下(小组交流) 3

21、、识别，加深体验动手操作 师:同学们的表现真不错。今天，一些图形娃娃也非常高兴来参加我们的活动，但它们有个要求(电脑出示P57“试一试”)要请同学们运用这节课所学的知识找出哪些是轴对称图形,大家能满足图形娃娃的要求吗,组长拿出信封中的图形，选择自己喜欢的图形动手折一折，然后在小组里说一说你选的是轴对称图形吗,为什么,(小组合作操作) 师:(点名回答)三角形是轴对称图形吗,为什么, (点名回答，学生投影展示) 师:那平行四边形是轴对称图形吗,为什么 (点名回答并投影展示) 师:(小结)通过刚才的操作，同学们知道怎样的图形才是轴对称图形吗, 生:(请23名学生说) 4、训练，巩固特征 师:看来同学

22、们学得真棒啊下面吴老师呢就要来考考大家了。 (1)师:(课件出示第58页第1题)这是我们生活中常会看到的一些图形，你能一眼就看出它们中哪些是轴对称图形吗,(直接提问，课件演示12个是轴对称图形，对有疑问的再演示) (2)师:同学们知道吗，我们学的英文字母，有很多也是轴对称图形呢就让我们在抢答游戏中把它们找出来吧，看谁的反映最快。(教师举字母卡片，学生抢答) summer of masonry construction, brick requires sufficient moist. 8.6.2.6 you must take the following measures to concret

23、e construction in summer high temperature impact on concrete a. hardening speed up, vibrating difficulties reduced bleeding, fast drying, easy to crack (plastic), high early strength, fast early hydration heat, less cooling, temperature increases rapidly, due to temperature difference cracks. B. pou

24、ring daytime high temperatures, due to the high temperature effect of concrete strength, stability, in varying degrees, on mixing processes, perfusion vibration and moisture conservation, effective measures should be taken. 2) main measures taken by a. temperature control the water temperature in yo

25、ur standard mix proportion of concrete 2 degrees, the concrete temperature 0.5 degrees. B. with the controlled addition of retarder agent can reduce the effects of concrete under high temperature, but make some performance degradation of concrete, so when you are using additives must be implemented

26、upon approval by the supervising engineer. C. time control suitable for work at night, should seek to reduce the mixing time and shipping time at high temperatures. D. strengthen the conservation and high temperatures after pouring in the early days of continuous water conservation to prevent surfac

27、e drying and covering thin-film wet grass bag to make it moist State in 24 hours. 8.6.3 8.6.3.1 winter construction measures in winter construction preparation 1) required winter construction materials, equipment, planning ahead of time comes into (3)师:(小结)为什么N、S不是轴对称图形呀, 生:(上来动手折一折)因为它们对折后不会完全重合。 师

28、:所以轴对称图形一定要对折后能完全重合。(学生一起说) 三、做一做内化新知 (1)教学例2做轴对称图形 师:刚才我们认识了轴对称图形，那大家想不想自己动手来做一个呢,请组长拿出信封中的材料，小组合作，各显神通吧，看哪个小组制作的轴对称图形最美了。(小组合作设计，教师巡视) 师:谁来把你的作品给大家展示一下呢, (请2种不同的方法到实物投影上展示，讲讲他们的做法) 师:(小结)看来同学们的方法可真多呀，我们做出来的轴对称图形对折后能(学生讲完全重合)(教师在实物投影上演示，并把一些学生的作品贴在黑板上) (2)师:昨天吴老师也剪了几个轴对称图形，(电脑出示P59第4题)下面的图案各是从哪张纸上剪

29、下来的，你能连一连吗,请同学们把书翻到第59页，在书上完成。(学生独立完成，再点名回答，电脑相机演示连线) 四、全课总结 师:今天，我们认识了轴对称图形，通过这堂课的学习，大家有什么收获呢,把你学到的本领告诉你的小组同学。 (学生小组交流，再点名回答) (对折后能完全重合的图形是轴对称图形，对折后的折痕所在的直线叫做对称轴，还学会了做轴对称图形。) summer of masonry construction, brick requires sufficient moist. 8.6.2.6 you must take the following measures to concrete co

30、nstruction in summer high temperature impact on concrete a. hardening speed up, vibrating difficulties reduced bleeding, fast drying, easy to crack (plastic), high early strength, fast early hydration heat, less cooling, temperature increases rapidly, due to temperature difference cracks. B. pouring

31、 daytime high temperatures, due to the high temperature effect of concrete strength, stability, in varying degrees, on mixing processes, perfusion vibration and moisture conservation, effective measures should be taken. 2) main measures taken by a. temperature control the water temperature in your s

32、tandard mix proportion of concrete 2 degrees, the concrete temperature 0.5 degrees. B. with the controlled addition of retarder agent can reduce the effects of concrete under high temperature, but make some performance degradation of concrete, so when you are using additives must be implemented upon approval by the supervising engineer. C. time control suitable for work at night, should seek to reduce the mixing time and shipping time at high temperatures. D. strengthen the conservation and high temperatures after po