最新苏教版三年级数学下册第二、三单元_教案

letters and calls, and do practical things for the masses combine good, effective through reaching people at the service of the \hird, foster the development of new energy, new General Secretary XI Jinping stressed development of innovation forest restructuring, revitalization of the old industrial bases in Northeast China is the State's major strategy, Central has issued comprehensive opinions of revitalizing Northeast China and other old industrial bases, the CPC Central Committee on revitalization in Northeast China were ... Vigorous determination does not waver, the work does not slacken off. Be firm with in the development has more to do with hard, and not muddle along, passive inaction. To rely on their own efforts, can't wait, can't wait, stand still. This not only provides new opportunities for development in our region, and gave us new requirements. We must seize the opportunity, full use of national policy, has to be more complicated, to start and target, give full play to theinitiative of leading cadres at all levels, active, active, focusing on building new momentum for development, accelerating transformation of forest development. To implement the new development philosophy. Philosophy is the action guide, new ideas and new developments. Carrying out innovation, coordination and development of green, open, shared ideas, must be measurable, direct action with new development concepts, training cadres. In a new development concept as a yardstick. Established in line with the new concept of evaluation system and evaluation criterion, embodies the new development policy, organization, mandate implementation, always measured by the new development philosophy, continuous correction of forest transition course. In a new development concept for the path command. As part of the implementation of the new development philosophy followed and action guidelines, firmly adjusted, corrected and reject unsuitable, inappropriate and even againstthe new development ideas, behaviors and practices, more pragmatic approach based on a broad vision, and creatively carry out ecological construction, industrial development, improving people's livelihood, such as the work to ensure that new development ideas take root in forest areas. In a new development concept for weapon training cadre. Education leaders \he new, nothing\es, enhancing vitality and power. Combined development \nd implementation \engineering\nd create \nvironment\hening on new development, and new economy concept of learning, and grasp and using, real put thought and action unified to new development concept up, at with new development concept armed himself, and guide practice, effective do advocate innovation, and focused on coordination, and advocate green, and thick plant open, and advance shared. Second, we must rely on Science and technology affects. Tchnical innovation is the promotion of economic transformation and upgrading, quality and efficiency \er\明确：买一套运动服和一双运动鞋因为选择不同，有多种选法。购买不同价格的运动服和运动鞋，剩下的钱是不同的。 （2）出示问题：小明和爸爸带300元，买一套运动服和一双运动鞋，最多剩下多少元？ 先让学生同桌互相讨论：最多剩下多少元？再指名汇报。 师小结：购买的商品价格最低，剩下的钱就最多。 提问：你能根据问题说出数量之间的关系，确定先算什么吗？ 学生独立思考后，把自己的想法在组内交流。 学生汇报交流： ①剩下的钱等于带来的钱减去用去的钱，可以先算用去多少元。 ②求最多剩下多少元，可以先算购买价格最低的运动服和运动鞋一共要用多少元。 引导：先想想每一步可以怎样算，再列式解答。 学生列式，指名回答，教师板书。 ①一共用去多少元？130+85=215（元） ②剩下多少元？300－215=85（元） （3）想一想：如果买3顶帽子，付出100元，最少找回多少元？ 提问：你能根据问题说出数量之间的关系，确定先算什么吗？ 学生汇报交流。 引导：先想想每一步可以怎样算，再列式解答。 ①最多用去多少元？24×3=72（元） ②最少找回多少元？100－72=28（元） 2.思考：回顾解决问题的过程，你有什么体会？ 学生自由发言，师小结：我们要在读题后要弄清题目里已知条件和问题分别是什么，可以从问题开始想，根据问题分析数量关系，确定先算什么。要根据题中的条件和问题，选择分析问题的思路。 三、反馈完善 1.完成教材第28页“想想做做”第1题。 根据问题说出数量关系式，并说说缺少什么条件。 （1）出示问题（1），引导分析：从“桃树比梨树多多少棵”想到的数量关系是什么？ 追问：有了这样的数量关系，要求这个问题，ivelihood, is related to people's well-being and social harmony and stability. We need to protect and improve the livelihood of the people as the starting point and ending point of transition and improve forest people's feeling and happiness. To promote poverty relief and development work. Implementing poverty alleviation crucial project is a major strategic decision made by the CPC Central Committee, is also determined by the provincial \nking and action to the requirements of the Central, provincial, resolutely win the poverty battle. The previous phase I to 18 stations, Tahe, Pine Ridge research, visited many of the poor, go, the heavier, more pressure. For poverty relief and development work, we must pay attention to it, always in mind, grasping hands, should not be blindly optimistic, there can be no slack. Poverty alleviation and development lies in precise, accurate. Present, in order to find out the real base of poor people as soon as possible, come up with feasible poverty standards, state card, built on the basis of document management. To firmly establish the \poverty reduction\he intensity of resource integration, and related funding, with limited funds wisely. By using a combination of employment, entrepreneurship for poverty eradication poverty eradication, education, poverty alleviation, medical aid of poverty means, due to effects of policies, those policies, ensure the completion of mission objectives for poverty eradication for the year. To actively promote the construction of new towns. In February this year, promulgated by the State Council on further promoting urbanization construction of new opinions, proposed to adhere to the people-centered, four modernizations synchronization, optimization, ecology civilization and cultural heritage of new urbanization path with Chinese characteristics. According to district-wide construction of civilized city and the beautiful countryside, further strengthening of urban transport, water supply and drainage and sewage, waste disposal ground, underground, such as infrastructure construction, strive to create a safer and more livable environment. To actively seize the full stop and opportunities for poverty alleviation and development, further efforts to increase forest villages merge, population to the County (district) Council sites and centres concentrated in villages and towns. Combined development of urban construction and tourism industries, careful planning and construction of a number of suitable for residential and farm tour towns and villages, forming one village one product, a feature pattern. Closer to the masses. Since last year, our in-depth implementation of the leading cadres of grassroots masses at work, solve the problems of a large number of people, get the masses give wholehearted support to and praise, this work will carry on, absolutely cannot or movement. Grassroots masses and cadres in combination with poverty reduction, combined with the steady work ofletters and calls, and do practical things for the masses combine good, effective through reaching people at the service of the \hird, foster the development of new energy, new General Secretary XI Jinping stressed development of innovation forest restructuring, revitalization of the old industrial bases in Northeast China is the State's major strategy, Central has issued comprehensive opinions of revitalizing Northeast China and other old industrial bases, the CPC Central Committee on revitalization in Northeast China were ... Vigorous determination does not waver, the work does not slacken off. Be firm with in the development has more to do with hard, and not muddle along, passive inaction. To rely on their own efforts, can't wait, can't wait, stand still. This not only provides new opportunities for development in our region, and gave us new requirements. We must seize the opportunity, full use of national policy, has to be more complicated, to start and target, give full play to theinitiative of leading cadres at all levels, active, active, focusing on building new momentum for development, accelerating transformation of forest development. To implement the new development philosophy. Philosophy is the action guide, new ideas and new developments. Carrying out innovation, coordination and development of green, open, shared ideas, must be measurable, direct action with new development concepts, training cadres. In a new development concept as a yardstick. Established in line with the new concept of evaluation system and evaluation criterion, embodies the new development policy, organization, mandate implementation, always measured by the new development philosophy, continuous correction of forest transition course. In a new development concept for the path command. As part of the implementation of the new development philosophy followed and action guidelines, firmly adjusted, corrected and reject unsuitable, inappropriate and even againstthe new development ideas, behaviors and practices, more pragmatic approach based on a broad vision, and creatively carry out ecological construction, industrial development, improving people's livelihood, such as the work to ensure that new development ideas take root in forest areas. In a new development concept for weapon training cadre. Education leaders \he new, nothing\es, enhancing vitality and power. Combined development \nd implementation \engineering\nd create \nvironment\hening on new development, and new economy concept of learning, and grasp and using, real put thought and action unified to new development concept up, at with new development concept armed himself, and guide practice, effective do advocate innovation, and focused on coordination, and advocate green, and thick plant open, and advance shard. Second, we must rely on Science and technology affects. Tchnical innovation is the promotion of economic transformation and upgrading, quality and efficiency \er\还缺少什么条件？ （2）学生独立分析问题（2），先根据问题写出数量关系，再说说缺少什么条件。 教师强调：在解答两步计算的实际问题时，关键是分析题中的数量关系，确定先算什么，再算什么。 2.完成教材第28页“想想做做”第2题。 让学生观察表格，并说明题意，明确计算的问题后，独立列式解答。然后请几名学生说一说解决问题的方法，给有困难的学生得到启发。 提示：要求足球组的人数，可以先算篮球组和田径组的人数之和，再将总人数减去篮球组和田径组的人数之和，即可求得足球组的人数。 3.完成教材第29页“想想做做”第3题。 让学生独立完成，完成后在小组内交流，并在交流中互相启发，加深理解。汇报解决问题的思路时，让学生说说每道题的数量关系。 师提示：这两题都要先算四个茶杯的总价。 四、反思总结 通过本课的学习，你有什么收获？ 还有哪些疑问？ 教学反思： ivelihood, is related to people's well-being and social harmony and stability. We need to protect and improve the livelihood of the people as the starting point and ending point of transition and improve forest people's feeling and happiness. To promote poverty relief and development work. Implementing poverty alleviation crucial project is a major strategic decision made by the CPC Central Committee, is also determined by the provincial \nking and action to the requirements of the Central, provincial, resolutely win the poverty battle. The previous phase I to 18 stations, Tahe, Pine Ridge research, visited many of the poor, go, the heavier, more pressure. For poverty relief and development work, we must pay attention to it, always in mind, grasping hands, should not be blindly optimistic, there can be no slack. Poverty alleviation and development lies in precise, accurate. Present, in order to find out the real base of poor people as soon as possible, come up with feasible poverty standards, state card, built on the basis of document management. To firmly establish the \poverty reduction\he intensity of resource integration, and related funding, with limited funds wisely. By using a combination of employment, entrepreneurship for poverty eradication poverty eradication, education, poverty alleviation, medical aid of poverty means, due to effects of policies, those policies, ensure the completion of mission objectives for poverty eradication for the year. To actively promote the construction of new towns. In February this year, promulgated by the State Council on further promoting urbanization construction of new opinions, proposed to adhere to the people-centered, four modernizations synchronization, optimization, ecology civilization and cultural heritage of new urbanization path with Chinese characteristics. According to district-wide construction of civilized city and the beautiful countryside, further strengthening of urban transport, water supply and drainage and sewage, waste disposal ground, underground, such as infrastructure construction, strive to create a safer and more livable environment. To actively seize the full stop and opportunities for poverty alleviation and development, further efforts to increase forest villages merge, population to the County (district) Council sites and centres concentrated in villages and towns. Combined development of urban construction and tourism industries, careful planning and construction of a number of suitable for residential and farm tour towns and villages, forming one village one product, a feature pattern. Closer to the masses. Since last year, our in-depth implementation of the leading cadres of grassroots masses at work, solve the problems of a large number of people, get the masses give wholehearted support to and praise, this work will carry on, absolutely cannot or movement. Grassroots masses and cadres in combination with poverty reduction, combined with the steady work ofletters and calls, and do practical things for the masses combine good, effective through reaching people at the service of the \hird, foster the development of new energy, new General Secretary XI Jinping stressed development of innovation forest restructuring, revitalization of the old industrial bases in Northeast China is the State's major strategy, Central has issued comprehensive opinions of revitalizing Northeast China and other old industrial bases, the CPC Central Committee on revitalization in Northeast China were ... Vigorous determination does not waver, the work does not slacken off. Be firm with in the development has more to do with hard, and not muddle along, passive inaction. To rely on their own efforts, can't wait, can't wait, stand still. This not only provides new opportunities for development in our region, and gave us new requirements. We must seize the opportunity, full use of national policy, has to be more complicated, to start and target, give full play to theinitiative of leading cadres at all levels, active, active, focusing on building new momentum for development, accelerating transformation of forest development. To implement the new development philosophy. Philosophy is the action guide, new ideas and new developments. Carrying out innovation, coordination and development of green, open, shared ideas, must be measurable, direct action with new development concepts, training cadres. In a new development concept as a yardstick. Established in line with the new concept of evaluation system and evaluation criterion, embodies the new development policy, organization, mandate implementation, always measured by the new development philosophy, continuous correction of forest transition course. In a new development concept for the path command. As part of the implementation of the new development philosophy followed and action guidelines, firmly adjusted, corrected and reject unsuitable, inappropriate and even againstthe new development ideas, behaviors and practices, more pragmatic approach based on a broad vision, and creatively carry out ecological construction, industrial development, improving people's livelihood, such as the work to ensure that new development ideas take root in forest areas. In a new development concept for weapon training cadre. Education leaders \he new, nothing\es, enhancing vitality and power. Combined development \nd implementation \engineering\nd create \nvironment\hening on new development, and new economy concept of learning, and grasp and using, real put thought and action unified to new development concept up, at with new development concept armed himself, and guide practice, effective do advocate innovation, and focused on coordination, and advocate green, and thick plant open, and advance shared. Second, we must rely on Science and technology affects. Tchnical innovation is the promotion of economic transformation and upgrading, quality and efficiency \er\ 第三单元 解决问题的策略 总第 15 课时 课 题 解决问题的策略——画线段图 课 时 第 2 课时 新授 课 型 1.经历探究和交流解决问题的过程，感受解决问题的策略，学会通过画线段图分析数量关系，掌握解决与倍有关的两步计算的实际问题及相应的变教学目标： 式问题。 2.感受数学与日常生活的密切联系，进一步增强学生对学习数学的兴趣和信心，初步形成独立思考的习惯和探究问题的意识。 重点难点： 教学重点：用线段图辅助解决两步计算的实际问题。 教学难点：分析数量关系。 板书设计： 教 学 过 程 一、谈话引入 谈话：同学们，咱们身上穿的上衣和裤子是谁买的？你有自己去买过吗？今天，我们就去商场看看。 二、交流共享 1.教学例2。 课件出示教材第29页例2的教学情境图，引导学生认真观察。 （1）理解题意。 让学生观察情境图，说说从中获得了哪些信息。 （2）画线段图。 提出问题：上衣的价钱是裤子的3倍，买一套衣服要用多少元？ 追问：你能理解买一套衣服的意思吗？ 引导：怎样解决这一问题呢？今天我们还请来了一位数学小助手，它的名字叫线段图。我们可以借助线段图来分析题目中的数量关系。 ①先画一条线段表示出裤子的价钱。（在黑板上画出表示裤子价钱的线段） ivelihood, is related to people's well-being and social harmony and stability. We need to protect and improve the livelihood of the people as the starting point and ending point of transition and improve forest people's feeling and happiness. To promote poverty relief and development work. Implementing poverty alleviation crucial project is a major strategic decision made by the CPC Central Committee, is also determined by the provincial \nking and action to the requirements of the Central, provincial, resolutely win the poverty battle. The previous phase I to 18 stations, Tahe, Pine Ridge research, visited many of the poor, go, the heavier, more pressure. For poverty relief and development work, we must pay attention to it, always in mind, grasping hands, should not be blindly optimistic, there can be no slack. Poverty alleviation and development lies in precise, accurate. Present, in order to find out the real base of poor people as soon as possible, come up with feasible poverty standards, state card, built on the basis of document management. To firmly establish the \poverty reduction\he intensity of resource integration, and related funding, with limited funds wisely. By using a combination of employment, entrepreneurship for poverty eradication poverty eradication, education, poverty alleviation, medical aid of poverty means, due to effects of policies, those policies, ensure the completion of mission objectives for poverty eradication for the year. To actively promote the construction of new towns. In February this year, promulgated by the State Council on further promoting urbanization construction of new opinions, proposed to adhere to the people-centered, four modernizations synchronization, optimization, ecology civilization and cultural heritage of new urbanization path with Chinese characteristics. According to district-wide construction of civilized city and the beautiful countryside, further strengthening of urban transport, water supply and drainage and sewage, waste disposal ground, underground, such as infrastructure construction, strive to create a safer and more livable environment. To actively seize the full stop and opportunities for poverty alleviation and development, further efforts to increase forest villages merge, population to the County (district) Council sites and centres concentrated in villages and towns. Combined development of urban construction and tourism industries, careful planning and construction of a number of suitable for residential and farm tour towns and villages, forming one village one product, a feature pattern. Closer to the masses. Since last year, our in-depth implementation of the leading cadres of grassroots masses at work, solve the problems of a large number of people, get the masses give wholehearted support to and praise, this work will carry on, absolutely cannot or movement. Grassroots masses and cadres in combination with poverty reduction, combined with the steady work of二 次 备 课 letters and calls, and do practical things for the masses combine good, effective through reaching people at the service of the \hird, foster the development of new energy, new General Secretary XI Jinping stressed development of innovation forest restructuring, revitalization of the old industrial bases in Northeast China is the State's major strategy, Central has issued comprehensive opinions of revitalizing Northeast China and other old industrial bases, the CPC Central Committee on revitalization in Northeast China were ... Vigorous determination does not waver, the work does not slacken off. Be firm with in the development has more to do with hard, and not muddle along, passive inaction. To rely on their own efforts, can't wait, can't wait, stand still. This not only provides new opportunities for development in our region, and gave us new requirements. We must seize the opportunity, full use of national policy, has to be more complicated, to start and target, give full play to theinitiative of leading cadres at all levels, active, active, focusing on building new momentum for development, accelerating transformation of forest development. To implement the new development philosophy. Philosophy is the action guide, new ideas and new developments. Carrying out innovation, coordination and development of green, open, shared ideas, must be measurable, direct action with new development concepts, training cadres. In a new development concept as a yardstick. Established in line with the new concept of evaluation system and evaluation criterion, embodies the new development policy, organization, mandate implementation, always measured by the new development philosophy, continuous correction of forest transition course. In a new development concept for the path command. As part of the implementation of the new development philosophy followed and action guidelines, firmly adjusted, corrected and reject unsuitable, inappropriate and even againstthe new development ideas, behaviors and practices, more pragmatic approach based on a broad vision, and creatively carry out ecological construction, industrial development, improving people's livelihood, such as the work to ensure that new development ideas take root in forest areas. In a new development concept for weapon training cadre. Education leaders \he new, nothing\es, enhancing vitality and power. Combined development \nd implementation \engineering\nd create \nvironment\hening on new development, and new economy concept of learning, and grasp and using, real put thought and action unified to new development concept up, at with new development concept armed himself, and guide practice, effective do advocate innovation, and focused on coordination, and advocate green, and thick plant open, and advance shard. Second, we must rely on Science and technology affects. Tchnical innovation is the promotion of economic transformation and upgrading, quality and efficiency \er\ 48元 裤子 ②上衣价钱的线段该怎么表示？画多长呢？（学生讨论） 引导：上衣的价钱是裤子的3倍，要画这样的3份。（指名板演） 48元 裤子 上衣 （3）列式解答。 你能根据问题说出数量之间的关系吗？你是怎么列式的？先算什么？再算什么？ 学生可能回答： ①方法一：先算买一件上衣要用多少元，48×3=144（元）；再算买一套衣服要用多少元，144+48=192（元）。 ②方法二：先算一套衣服一共有几个48,1+3=4；再算买一套衣服要用多少元，48×4=192（元）。 2.想一想：如果求买一件上衣比买一条裤子多用多少元，应该怎样解答？ （1）提问：你能说出这道题的数量关系吗？ 学生讨论，说出数量关系式。 指名回答，教师板书： 上衣的单价－裤子的单价=上衣比裤子多用多少元 引导思考：在这个数量关系里，哪一个量是直接告诉我们的？（裤子48元）要先求的是哪一部分？（上衣的价钱）和上面一题相比，什么不变？（已知条件）什么变了？（所求问题）问题改了，线段图要不要改？怎样改？ 学生尝试画图，教师巡视指导。 提问：你能指出所求问题是哪一部分吗？ 根据学生的回答，教师在黑板上改线段图： （2）追问：现在你能解答这道题吗？先算什么？再算什么？ 学生交流反馈回答，教师板书。 ？元 ivelihood, is related to people's well-being and social harmony and stability. We need to protect and improve the livelihood of the people as the starting point and ending point of transition and improve forest people's feeling and happiness. To promote poverty relief and development work. Implementing poverty alleviation crucial project is a major strategic decision made by the CPC Central Committee, is also determined by the provincial \nking and action to the requirements of the Central, provincial, resolutely win the poverty battle. The previous phase I to 18 stations, Tahe, Pine Ridge research, visited many of the poor, go, the heavier, more pressure. For poverty relief and development work, we must pay attention to it, always in mind, grasping hands, should not be blindly optimistic, there can be no slack. Poverty alleviation and development lies in precise, accurate. Present, in order to find out the real base of poor people as soon as possible, come up with feasible poverty standards, state card, built on the basis of document management. To firmly establish the \poverty reduction\he intensity of resource integration, and related funding, with limited funds wisely. By using a combination of employment, entrepreneurship for poverty eradication poverty eradication, education, poverty alleviation, medical aid of poverty means, due to effects of policies, those policies, ensure the completion of mission objectives for poverty eradication for the year. To actively promote the construction of new towns. In February this year, promulgated by the State Council on further promoting urbanization construction of new opinions, proposed to adhere to the people-centered, four modernizations synchronization, optimization, ecology civilization and cultural heritage of new urbanization path with Chinese characteristics. According to district-wide construction of civilized city and the beautiful countryside, further strengthening of urban transport, water supply and drainage and sewage, waste disposal ground, underground, such as infrastructure construction, strive to create a safer and more livable environment. To actively seize the full stop and opportunities for poverty alleviation and development, further efforts to increase forest villages merge, population to the County (district) Council sites and centres concentrated in villages and towns. Combined development of urban construction and tourism industries, careful planning and construction of a number of suitable for residential and farm tour towns and villages, forming one village one product, a feature pattern. Closer to the masses. Since last year, our in-depth implementation of the leading cadres of grassroots masses at work, solve the problems of a large number of people, get the masses give wholehearted support to and praise, this work will carry on, absolutely cannot or movement. Grassroots masses and cadres in combination with poverty reduction, combined with the steady work of