在日常学习、工作或生活中，大家总少不了接触作文或者范文吧，通过文章可以把我们那些零零散散的思想，聚集在一块。相信许多人会觉得范文很难写？下面我给大家整理了一些优秀范文，希望能够帮助到大家，我们一起来看一看吧。
有理数的减法教学设计 四年级小数加减法教学设计篇一
（一）通过教学，学生初步认识0的意义。
（二）会计算有关0的加、减法。
（三）学会0的写法。
重点：初步了解0的意义及有关0的加、减法。
难点：0的写法。
（一）教具：3个放大的茶碗、茶盘图、气球图、蜡笔盒图、放大直尺。
（二）学具：每人准备一把小直尺；0~5的数字卡片。
（一）复习准备
1、看图写数：
2、填空：
3、口算：
4+1=
2-1=
3-2=
1+2=
2+2=
5-1=
3+2=
5-4=
3-1=
（二）学习新课
启发谈话：盘子里有两个杯子，用数字2来表示，盘子里有一个杯子，用数字1来表示。如果盘子里一个杯子也没有（出示）用什么数字来表示呢？（这时肯定会有同学说出用零来表示）对！用零来表示，这节课我们就来学习“0的认识和有关0的加、减法”（贴出课题）
1、认识0。
师说：盘子里一个杯子也没有，我们可以用数字“0”来表示，板书：0。
师说：这个数字读作“零”，“0”表示没有。“0”和1，2，3，4，5一样，也是一个数。但它表示什么呢？（表示没有）
（1）引导学生结合生活实际说说“0”的用法和意义。
师说：我们在日常生活中经常会用到0这个数字，比如；妈妈买回5个苹果，吃了5个，还剩0个。小华有3支铅笔，用了3支，还剩0支。你们一定还会说出许多这样的例子。现在我们分小组议论，看谁说得最好。
议论后，指名4~5人说。
（2）拿出自己的小直尺。
师说：刚才同学们说得非常好，你们对0有了初步的认识。0可以表示没有。0还可以表示什么呢？请大家拿出你的小直尺。
看一看，0在什么位置？在这里它还可以表示什么？
（3）出示直尺放大图。
师说：请大家看放大直尺图，0在这里表示一段也没有。它还可以表示起点。表示量东西从这里开始。
师问：这个0应排在谁的前面？为什么排在1的前面？（因为0是起点）
指名数直尺上的数：从0~5。
齐读：0~5，5~0。
（4）指导0的书写。
老师边范写边说：写0时，从上到下，从左到右、起笔收笔都要相连，写成椭圆形。
自己在课桌上练习写0，注意笔顺。
在书上练习格描写0。
2、学习有关0的加减法。
（1）学习同数相减等于0的减法。
出示小朋友拿气球图：
师问：
①第一幅图中的小朋友手里有几个气球？
②第二幅图中的小朋友手里有几个气球？
③把这两幅图连起来看，是什么意思？（小朋友手里原来有2个气球，飞起2个）
④原来有2个气球，飞起2个，可以提出什么问题？（还剩几个？）
⑤求还剩几个？用什么方法计算？怎样列式？
板书：2-2=0。
指名说：算式中的2，2和0各表示什么？
⑥2-2=0为什么用0表示？
师说：2去掉2就没有了，所以用0表示。
摆一摆：
同学们在自己的课桌上先摆3根小棒，再拿走3根，还剩几根？
算式怎么列？板书：3-3=0。
齐读：2-2=0，3-3=0。
师说：你们还能想出几减几等于0的题吗？
学生说，老师板书：
1-1=0 5-5=0
4-4=0 0-0=0
师说：这些都是同数相减得数是0的题。
（2）学习一个数加0或减0。
出示蜡笔盒图：
师问：
①左边盒里有几支蜡笔？右边盒里有几支蜡笔？一共有几支蜡笔？
②求一共有几支蜡笔，用什么方法计算？怎样列式？板书：4+0=4、
指名说：算式中各数表示什么？
老师把两个盒子调换位置：
师问：
①谁能看图再列一道算式？
指名说，板书：0+4=4、
②4加0为什么还等于4？（因为4加0就是4加没有，还应该是原来的数。）
③那2+0，5+0，0+3呢？
师说：这几道题都是一个数加零的加法。
想一想：一个数减零应怎么算呢？
板书：5-0=□。
指名说：5-0=5。
师问：为什么5减0还得5？（因为从5里去掉0个，就是一个也没去掉，所以还是5。）
师问：4-0呢？6-0，7-0呢？
今天我们学习了0的认识和有关0的加减法。知道了同数相减（指板书）等于0，一个数加0还得这个数；一个数减0还得这个数。下面比一比看谁学得最好。
（三）巩固反馈
1、拿出0~5的数字卡片，按从小到大的顺序排一排。
2、看图列式计算：
3、口算：
4+0=
3-3=
2-0=
0+3=
5-5=
1-0=
2+0=
0-0=
5-0=
0+0=
4-4=
3-0=
4、做练习五第1，4题。
本节课是学习0的认识及有关0的加、减法。课堂设计是这样安排的：
一、分三个层次进行新课。
第一层，认识0；
第二层，教学相同数相减等于0；
第三层，教学一个数加0或减0。
0的认识对低年级学生来说比较抽象，所以要通过直观演示、观察实物图、动手操作等方法使学生从感性上对0有初步认识。
二、在教学有关0的加、减法时，讲完例题后启发学生动脑筋自己编题，自己计算。
三、在讲完4+0=4这道题后，设计了把两个蜡笔盒调换位置，让学生列出0+4=4进一步加深理解对“调换两个加数的位置，得数不变”的理解。
四、在巩固练习环节，除完成练习五第1，4题的作业，还增加了看图列式计算和口算练习，让学生进一步理解有关0的加减含义。
有理数的减法教学设计 四年级小数加减法教学设计篇二
1、通通过整理和复习，使学生更加熟练掌握两位数加减，整十数和两位数加减一位数的口算方法。通过整理和复习，使学生更加熟练掌握两位数加减，整十数和两位数加减一位数的口算方法。
2、培养学生初步的分析、比较、综合等能力。
掌握加法和减法的口算方法。
我们学过100以内的加减法口算，现在我们来复习一下。
（一）先想一想，我们学过哪些加法口算？让学生举例说：
出示第一组题：50+20、57+20、57+2、57+9先要求学生口算各题，并说出计算过程，再让学生比较。
提问：它们在计算方法上有什么相同和不同的地方？
老师结合学生讨论概括出：
1、相同点：几个十和几个十相加，几个一和几个一相加，也就是要把相同单位的数相加。
2、不同点：整十数加整十数，只要把几个十和几个十相加，两位数加整十数，把几个十和几个十相加，个位上的数字不变。两位数加一位数，只需把几个一相加，相加不满十的，十位上的数字不变，相加满十的，十位上的数字增加一。
（二）想一想，我们学过哪些减法口算？让学生举例说：
出示第二组题：50-20、57-20、57-2、57-9
先要求学生口算，再让学生比较。提问：它们在计算方法上有什么相同和不同的地方？
老师结合学生讨论概括出：
1、相同点：几个十和几个十相减，几个一和几个一相减，也就是要把相同单位的数相减。
2、不同点：整十数减整十数，只要把几个十和几个十相减。两位数减整十数，把几个十和几个十相减，个位上的数字不变。两位数减一位数，只需把几个一和几个一相减，十位上的数字不变，个位相减不够减，十位上的数字要减少一。
（三）让学生比较两组题
提问：这两组题的口算方法又有什么相同和不同的地方？
概括出：相同点：相同单位的数才能相加减
不同点：个位相加满了十，十位上的数字增加，个位相减不够减，十位上的数字要减少一。
（一）
加数50423576923
加数203038817
和
1、提问：已知两个加数，求和用什么方法算？
2、学生独立计算。
3、提问：42+30，怎样想能很快算出得数？（整十数相加，只需把40和30相加，个位上的数字不变，得72）
4、提问：76+8怎样想能很快算出得数？（加的是一位数，把6和8相加得14，满了10，十位上应增加1，得84）
（二）
被减数607268413065
减数40507348
差
1、提问：已知被减数和减数，求差用什么方法算？
2、学生独立计算。
3、提问：72-50，怎样想能很快算出得数？
41-3，怎样想能很快算出得数？
（三）引导学生对比小结：
口算既要准确，又要迅速，就必须熟练掌握计算方法，还要看清符号。特别要注意，个位相加满了10，在十位上要添上1，个位上不够减，十位上要减1。
三、加强练习，提高口算能力。
（1）教科书p78页，第1题。
（2）教科书p80页，第5题。
学生直接在课本上写得数，并统计5分钟完成的人数。
有理数的减法教学设计 四年级小数加减法教学设计篇三
人教版小学数学第十册第131－132页。
1．通过学生自主探究，掌握异分母分数加减法的计算方法和算理。
2．能正确计算异分母分数的加减法。
3．初步渗透转化、建模等数学思想，提高学生解决问题的能力。
一、创设情境，导入新课
1．谈话导入。
同学们，同分母分数加减法为什么能直接相加减?(分母相同，即分数单位相同)怎样计算异分母分数加减法呢?请你们拿出两张同样大的长方形纸分别折出1/2和1/4，再用两张同样大的正方形纸分别折出1/3和1/9，折好后涂色表示这几个分数。
2．小组活动：学生交流各自的表示方法。
3．教师设问：这里的1/2和1/4、1/3和1/9能直接相加吗?为什么?(分母不同，即分数单位不同，不能直接相加) 揭示课题：异分母分数加减法。
[评析：课始开门见山，以设问的形式，从学生已有的旧知切入新知。通过折纸活动，将学生带入求知的情境中，既复习了旧知，又引发了新旧知识间的矛盾，激起了学生的认知冲突和学习欲望。]
二、合作学习。探究新知
1．分组讨论1/2+1/4，并用实验说明计算方法。
(引导学生用前面折纸并涂色的长方形纸来验证计算方法，分组派代表汇报计算情况)
2．同理分析：1/3+1/9=3/9+1/9=4/9。结合板书讨论：
(1)从等式的左边到等式的右边，实际是做了什么?(通分)
(2)谁来说说这种方法的道理?(可结合学具图理解)把1/2化成2/4，这样平均分的份数相同，也就是说分数单位相同。因此，2个1/4与1个1/4合起来就是3个1/4，即3/4；第二题是3个1/9与1个1/9合起来是4个1/9，即4/9。
3.验算1/2+1/4=3/4。
(1)交换加数位置。
1/4+1/2=1/4+2/4=3/4
(2)用减法验算。(你会算吗?有困难的小组帮忙)
3/4-1/2=3/4-2/4=1/4
3/4-1/4=2/4=1/2
4．你现在知道异分母分数加减法怎样计算吗?
完成板书：异分母分数加减法
↓通分
同分母分数加减法
[评析：承用前面的折纸，引导学生直观地看出计算结果。通过相互述说算理和检验计算过程，使学生不仅掌握了异分母分数加减法的计算法则，知道怎么算，而且懂得了为什么这样算的道理。]
三、巩固练习。形成技能
1．基础练习。
1/3+1/4
5/6+3/8
11/12-5/6
3/4-2/5
1-1/6
(先让学生独立完成，然后指名板演各题的计算过程，注意对计算中的错误和不规范的书写进行纠正。并引导学生总结各类题型的计算方法及技巧)
2．深化练习。
出示异分母分数加减法算式让学生进行计算，并让学困生说说异分母分数的计算法则。(要求能说出先通分化成同分母分数，再相加减)
有理数的减法教学设计 四年级小数加减法教学设计篇四
讲例1—例3，处理第20页至21页
1认识减号和减法算式：
2探索减法的算法
3养成看图的习惯，能提出数学问题，并会解答
从连动性的三副图中提出减法问题的算理
例1多媒体课件；送信卡片；找朋友卡片
一前提测评；5分
小朋友，前面我们学习了5以内的数，想一想，还会数吗？
1从0数到5
2倒数呢
3听师拍了几下
4师说数，生拍
5对口令，找5的对子数
二引入（2分）；请看；这有几支铅笔？（5支）送给小朋友3支，还剩几支？会算吗？这节课我们就一齐来探索5以内的减法。比一比，看谁这节棵听讲最专心，举手最积极，回答音最亮
三新课达标20分
（一）学例1
1请看大屏幕：从图中你看到了什么？
2哪副是第一副？你是怎么知道的？什么记号？
3你能看着这两幅图提个数学问题吗？
4用算式表示：3—1=2
5认识减号—表示从3里面减去1个还剩2个
6读算式；领读，齐读，男生读，女生读，指名读
（二）学例2
1齐读算式5—2=
2算式表示什么？
3四人一组拿出小棒动手摆一摆
4交流；5—2=3
5想一想除了摆小棒还可以怎么算？
6汇报用数数的方法，还可以用分成
7看算式摆小棒5—1=5—4=
8口算4—3=3—2=4—1=
（三）学例3
1师指导生在田字格里书写算式，先描在算，比一比看谁写得最规范，最标准
2评比
3听算5—3=4—2=3—2=
四课间放松11分一二拍拍手
三四点点头
五六甩甩背
七八跺跺脚
九十我坐直
五达标训练8分
1填在书上书第22页
2找朋友游戏（师那得数找算式）
3送信游戏（邮筒上写得数站在前，听口令，拿着信封上写着算式的学生上前投信。其余学生说；小小邮递员
真是不简单
送信快又准
人人都称赞
4夺红旗比赛男女生各五名
六布置作业3分
口算；5—4=4—3=3—2=2—1=5—3=4—2=5—1=
七全课
总结1分
通过这节课的学习，你学到了什么，有什么收获？有理数的减法教学设计 四年级小数加减法教学设计篇五
教科书第53—55页
1、会用计算器进行一些稍复杂的小数加、减法计算。
2、让学生体验用计算器进行计算的方便与快捷，进一步培养对数学学习的兴趣，感受计算器在人们生活和工作中的价值。
［例题通过相对复杂的问题情境，引入用计算器计算小数加、减法，教给学生在计算器上按出整数部分是0的小数的简便按法，再用计算器解决小数加法的实际问题。“试一试”继续通过例4的问题情境，引导学生借助计算器解决小数减法的实际问题。
谈话：同学们都有去超市购物的经验，购完物，营业员都能借助计算器准确、快速地算出应付的价钱，今天我们也来用计算器解决一些计算问题。
1、教学例4
（1）出示例题，理解题意。谈话：怎样用计算器算出她一共用了多少元？
（2）先让学生独立思考，然后指名回答。在全班交流中达成共识：只要把“金额”一栏的数据加起来。
（3）提问：那在计算器上，怎样才能按出买铅笔的钱呢？先让学生自己试着按一按，再交流方法。学生的方法可能有：①按照“0”、“·”、“8”、“0”的次序按键。②先按“·”再按“8”，显示“0·8”，就是买铅笔的钱数。
（4）尝试计算。
（5）集体校对。提问：怎样才能计算得又对又快？学生的想法可能有：①先记牢这个数，然后再按。②看到零点几的小数，可以直接按小数点和小数部分，这样能节省计算时间。③按好一个数，还要看看显示屏，核对一下。④算完还可以用计算器再算一遍。
2、完成“试一试”
（1）提问：如果李芸付出100元，应找回多少元？请你用计算器算一算。
（2）学生尝试用计算器计算。
（3）小结：用计算器计算这些比较复杂的小数加减法（出示课题），确实非常快捷，正确率也高。
［设计意图：用计算器进行计算时，为确保计算的快捷和正确，核对和验算很重要，通过学生的讨论和交流使学生获得准确灵活的计算方法。
学生已经有了用计算器计算的基础，因此这个环节以尝试使用、相互交流为主要学习方式，顺应了学生使用计算器的需要，也为学生提供了很好的相互启发、相互学习的机会。］
1、完成“练一练”
（1）让学生用计算器独立计算，在书上记下每题的得数。
（2）交流计算的注意点。在讨论交流中使学生明确：先记牢一个数，然后再按，按好后注意核对，提高计算的正确率。
2、完成练习九第6题
（1）提问：你是怎样列式的，结果是多少？
（2）学生各自用计算器计算这四题。
（3）同桌互相出题并借助计算器解答。
3、练习九第8题
（1）理解题意。先让学生观察这张收支情况统计表，说说每栏表示什么含义。
（2）思考：怎样算“小明开学缴费”后的余额？先让学生独自思考，再指名回答。在交流中明确：只要用上月的余额1203·5元减去支出的100元，就能算出小明开学缴费后的余额。
（3）明确各项余额的算法。让学生挑选一栏和同桌说说怎样算它的余额？重点解决“合计收入”“合计支出”的算法。
（4）学生独立用计算器算出每次收支后的余额，集体校对答案。
（5）拓展延伸。谈话：我们也能像小明一样，学记自己的经济小帐本。设想一下，如果要你来统计每月零花钱的收支情况，你准备怎样来设计这张统计表？希望同学们持之以恒记好经济帐，合理支配自己的零花钱。
［设计意图：通过用计算器计算开支情况，使学生感受到计算器在人们生活和工作中的价值。并且联系生活用数学，让学生学记经济帐，从而不断增强学生学数学、用数学的自觉性。］
4、练习九第9题
（1）学生先用计算器计算前三题。
（2）汇报结果。前三题的答案依次是1·89、2·889、3·8889。
（3）提问：观察一下，这三题的答案有什么规律？学生的想法可能有：①个位上的数一个比一个多1。每个数的末尾都是9。②小数中间“8”的个数和个位上的数一样。
（4）根据这些规律填出最后一题的得数。
［设计意图：让学生用计算器计算来探索一些计算中的规律，一方面可以进一步培养学生自主探索问题结论的意识能力，另一方面可以使学生发现计算过程中的一些“有趣”的现象，从而使学生初步体会到数学是一门有规律的科学，产生对数学学习的好奇心，激发学习数学的兴趣。］
今天我们用计算器计算了一些比较复杂的小数加减法。通过这节课的学习，你有什么体会？
练习九第7题。
有理数的减法教学设计 四年级小数加减法教学设计篇六
同分母分数加、减法
分数数的加法和减法异分母分数加、减法
分数加减混合运算
1．理解分数加、减法的算理，掌握分数加、减法的计算方法，并能正确计算出结果。
2．理解整数加法的运算定律对分数加法仍然适用，并会运用这些运算定律进行一些分数加法的简便运算，进一步提高简算能力。
3．体会分数加、减法运算在生活、生产中的广泛应用。
1．加强直观，凸显过程，培养数感。
学习分数加、减法的关键是让学生理解“只有相同单位的数才可直接相加、减”的算理。为了帮助学生理解，在教学过程中，一方面应注意充分利用数形结合的方法，加强直观认识，借助直观图的演示或学具操作，建立表象，理解算理；另一方面要为学生创设参与、探索、概括计算法则的空间，让学生经历观察、操作、猜想、验证的过程，鼓励学生有条理地表达自己的思考过程，揭示算理，概括法则，培养数感。
2．加强对比，沟通联系，促进迁移。
本单元中教材从同分母分数加、减法的法则推导到异分母分数加、减法的法则推导，从整数和小数加、减法的意义，计算法则，加减混合运算顺序到分数加、减法的计算法则、加减混合运算顺序直至加、减法运算定律和性质的推广，无一不体现着知识之间的内在联系。教学中，应充分利用这种内在联系，注意对比和沟通，利用学生已有的知识和经验，感悟新旧知识之间的共同点，让学生通过自己的探索学习新知，这样不仅省时、突出重点，还培养了学生学习过程中的迁移、类推能力。重视口算，强化关键，培养能力。本单元中，分数加、减法中的分子、分母一般都不大，很多计算题可以直接口算出来，因此在计算正确的基础上，提倡能口算的尽量口算，以便提高学生的计算熟练程度和口算能力。
除重视口算训练外，还应注意练习的针对性，抓住分数加、减法的重点、难点和关键进行练习。当学生计算熟练后，要注意指导学生的计算法则，适当省略式题计算的思考步骤，简缩思维过程，培养求简思维。同时根据计算式题的具体特点，鼓励学生选择灵活的算法或进行简便运算，培养学生的计算能力及思维的灵活性。
4．认真审题，自觉检查，培养习惯。
在教学过程中，老师要重点关注学生审题能力的培养，要引导学生整体感知算式的特点，确定题目的运算顺序。教学中还应重视教给学生险验的方法，培养学生良好的检验习惯。
［课时安排］
1．同分母分数的加、减法……………………………………………………………3课时
2．异分母分数的加、减法……………………………………………………………2课时
3．分数加、减混合运算………………………………………………………………2课时
4．第五单元实力评价…………………………………………………………………1课时
1、同分母分数的加、减法
第一课时
同分母分数加、减法
（一）教材第104一106的内容及第108页练习二十一的第1、2题。
1．通过教学，使学生初步理解同分母分数相加减的算理，掌握同分母分数加、减法的计算法则。
2．培养学生数形结合的数学思想能力。提高学生迁移类推的能力和计算能力。
3．培养学生规范书写和仔细计算的良好习惯。
理解同分母分数加、减法的算理和计算方法。
多媒体课件。
（一）导入
(1）的分数单位是（），它有（）个这样的分数单位。
(2）(）个是，里有（）个。
(3）3个是（），是4个（）。
2．谈话：我们在三年级已经学习过同分母分数的加、减法，今天这节课我们继续研究这个知识。
（二）教学实施
1．出示例1。
提问：观察图，你都知道了哪些数学信息？
（把一张饼平均分成8份，爸爸吃了张饼，妈妈吃了张饼，求爸爸和妈妈共吃了多少张饼。
提问：要求爸爸和妈妈共吃了多少张饼，怎样列式？为什么？
学生思考并口答：＋，表示把两个分数合并起来，所以用加法计算。
提问：你能算出结果吗？怎样想的？
学生可以这样思考：是1个，是3个，合起来也就是。
提问：＋的和是，为什么分母没变，分子是怎样得到”的？
（因为和的分母相同，也就是它们的分数单位相同，所以可以直接用两个分子相加，分母不变。）提问：你会写出计算过程吗？
板书：＋===
利用多媒体课件演示上面的计算过程：
观察图可以看出结果是，也就是。注意：计算结果，能约分的要约成最简分数。
2．提问：通过解答上题，想一想分数加法的含义是什么？怎样计算同分母分数加法？
小结：分数加法的含义与整数加法相同，都是表示把两个数合并成一个数的运算。在计算同分母分数加法时，分母不变，只把分子相加。
3．出示例2。
请学生看题，试列式并计算。
请学生汇报计算过程：—===
有理数的减法教学设计 四年级小数加减法教学设计篇七
教学目标：
１、使学生掌握估算的方法，认识估算的必要性。
２、使学生能结合具体情境进行估算，并能解释估算过程。
３、培养学生估算能力，运用估算知识解决实际问题的能力以及口头表达能力。
４、感受算法的多样化，培养学生求异思维能力。
1、创设情境：（）出示口答：下面的这些数是最接近哪个整十数。
４９最接近（ ） ８２最接近（ ） ６８最接近（ ）
１１最接近（ ） ７３最接近（ ） ２６最接近（ ）
２、出示课本插图：引导学生找出条件和问题并提出学习目标。
师：今天我们就来学习加减法估算，你们想知道哪些问题？
生答师整理：（１）什么是估算？（２）学习怎样进行估算？
１、小组学习交流：
自主解答例题４，可能出现以下答案：
（１）把２８看作３０，４３看作４０进行估算1００-３０-４０＝３０
（２）先算热水瓶和烧水壶大约花了７０元，３０+４０＝７０，１００-７０＝３０
２、全班展示成果，提出质疑：
（１）还可以怎样算呢？
（２）全班同学共同总结估算的方法。
１、运用估算的方法各小组完成“做一做”及练习六第１~３题
２、小组内再展示交流。
１、全班展示错例。
２、分析总结错因，巩固提高。
有理数的减法教学设计 四年级小数加减法教学设计篇八
苏教国标本五年级上册p40~41 例1及练习六
1、使学生经历探索小数加减法计算方法的过程，体会小数加减法与整数加减法在算理上的联系，初步掌握小数加减法的计算方法，能运用计算解决一些简单的实际问题。
2、使学生进一步增强运用已有知识和经验探索并解决新问题的意识，不断体验成功的乐趣。
3、在自主探索、合作交流中体验成功学习的乐趣，增强学好数学的信心。
小数加减法的意义和计算方法。
“相同单位要对齐”的道理。
1、情境：开学前，同学们都要去商店买一些学习用品。（出示情境图）你能从中获得哪些信息？
2、信息：一枝钢笔16元，一个计算器138元，一本笔记本3.4元，一个讲义夹4.75元。
3、问题：根据这些信息，你能提出只用一步计算的加减法数学问题吗？并请说出算式。
4、复习：同学们问题意识很强，提出了很多问题，老师从中选择了一些，138+16,4.75+3.4,4.75-3.4,138-4.75,哪道算式我们已会列竖式计算了？谁来试试。（生板演）请其他同学注意观察，他是怎样列竖式的？他做得对吗？（板演者介绍方法）你是怎样列竖式的呢？（强调：相同数位对齐，从个位算起）
5、揭题：同学们整数加减法学得很扎实，剩下的三题都涉及到小数，今天我们就研究这样的计算，给个恰当的课题。（板书：小数加法和减法）
1、教学4.75+3.4
尝试练习：我们先讨论4.75+3.4，行吗？你会用竖式计算吗？算之前，先估一估结果是多少。（学生尝试练习，教师巡视。）
比较分析：（教师展示学生的做法，估计有三种）
引导质疑：同一道题，怎么可能出现截然不同的结果，会不会算错了，回头检查计算过程。小组内交流一下，你认为哪种做法正确，有令人信服的理由吗？
互动交流：⑴辩一辩：说出你的答案对错的理由，预设方案：估算，转化成整数计算，小数的意义等。
⑵比一比：对比算式，竖式不同在哪？你认为哪种竖式对了，哪种错了，为什么？
⑶想一想：②③两种列式方法，可能是怎样想的？与整数加法列式有矛盾吗？（在学生不同的“算法”比较中，突出“相同数位对齐，相同的计数单位才能相加，小数点需要对齐”的算理。）
正确算法：现在小数加法列竖式计算你会了吗？请②或③做法的同学说给老师板演，教师注意提醒学生用直尺打上横线。
归纳算理：小数加法是怎样计算的？（1~2名同学用自己的语言叙述）
实践体验：如果把3.4改成3.45，你会算吗？算之前还是先估一估计算的结果。展示两种做法，提醒学生根据小数的基本性质，对结果进行化简。
2、教学4.75-3.4
尝试练习：你能象计算小数加法一样列竖式算4.75-3.4吗？先估计一下，差大约是多少？再试试看。（尝试练习，板演）做好的同学小组内交流计算方法。
归纳算理：请板演的同学说一说是怎样列竖式计算的？为什么要将小数点对齐？（1~3名同学说说）
验算：我们学计算，不仅要学会计算的方法，还要通过计算来养成认真做事的好习惯，会验算吗？怎样验算？下面请你用喜欢的方法验算4.75-3.4。通过验算你做对了吗？
1、说一说，小数加减法的计算方法。与整数加减法有什么相同点？（板书：相同数位对齐，从低位算起）计算小数加减法要注意什么？（列式时小数点对齐，得数中不要忘记点小数点，计算结果能化简的要化简）
2、算一算
3、改一改
4、用一用
① 在北京奥运会男子50米三种姿势射击决赛中，我国选手邱健以99.5环的成绩获得冠军，乌克兰选手以98.4环的成绩屈居亚军，请算出他们的成绩相差多少环？
②“神舟七号”飞船预定于今晚（9月25日）发射升空，将在距地面约341千米的高空绕地飞行，它的飞行高度比“神舟六号”约少3.73千米。“神舟六号”的飞行高度约离地面多少千米？
③
从射阳到盐城走哪条公路比较近呢？
5、赛一赛
比赛要求：小组接力，自己要确保计算正确，后面的同学先要检查前面同学计算是否正确再做。
（1）检查评比 （2）联系反思，通过比赛，你有什么感想？
通过今天的学习，你还有哪些收获？
我们一起解决了三个问题，剩下138-4.75这道题，同学们课后可以先尝试着做一做，如果遇到困难，可以先预习下一节课的内容。
教后反思：
本节课本着“真实、朴实、扎实、常态、有效”的原则，力图使计算教学返璞归真，关注数学的本质来设计教学，我在以下几方面做了一些尝试。
1、抓住算理本质，重组教材，促进新知的内化建构。
小数加减法教学的切入点是“计数单位相同的数，才能直接相加减”，全课因此始终围绕这一算理为主线。课前谈话中的“1（）+1（ ）=11（ ）”的目的是让学生在游戏中感悟“只有计数单位相同的两个数才能直接相加减”。为了沟通小数加减法与整数加减法在计算算理上的一致性，我们大胆改编课本中的素材，去掉了水彩笔2.65元，添加了计算器138元。用意在于，学生根据情境所提供的信息，提出的一步加减法计算问题中，出现了整数加减整数，整数加减小数，小数加减小数三种类型。教师从学生提出的问题中抽取了四个作为今天研讨的话题，即138+164， 75+3.4,4.75-3.4,138-4.75。学生列竖式板演138+16后讲清整数加减法的计算方法，特别是相同数位对齐这个核心算理，为探究新知做知识铺垫。然后对比引入新知，学生凭借已有经验尝试练列竖式计算4.75+3.4。课堂中正如课前所调查的那样，学生出现了三种不同的算法，教者引导学生检查计算过程看计算有无错误，进一步激发学生从估算、化成元角分采用整数算、从相同计数单位相加等角度去寻找算理，通过生生、师生之间的互动，去判断、分析、理解、建构小数加法正确的计算方法，内化计算小数加法时要相同数位对齐（小数点对齐）的要求。这部分教学设计时就想成为本课的亮点之一。
2、关注学生学习，强化互动，促进三维目标的落实。
整节课我能小心翼翼地呵护孩子的学习热情，“没有提前的渗透，没有矫情的暗示”，全力以赴保护好学生的自尊心、自信心，注意面向全体，倾心聆听后进生的发言，给他们改正错误，成功展示自己的机会，通过剖析错误，从而建立起正确的价值观，
让所有学生在学习中体验数学的价值。在最近发展区上做文章、下功夫，注重发挥学生的独立性，培养学生的独立学习能力以及学习责任感，加强教学的针对性，使教学走在发展的前面，使学生在本节课中有实实在在的认知、收获和数学感悟。赛一赛后请获得胜利和失败的小组分别谈感受，以加强团队精神、精确计算等方面的教育。力图体现北师大周玉仁教授所提倡的：凡是学生能自己探索得出的，决不替代；凡是学生能独立思考的，决不暗示。为学生多创造一点思考的时间，多一点活动的余地，多一点表现自我的机会，多一点体尝成功的愉悦。
3、注重思维训练，加强估算，促进计算好习惯养成。
数学是思维的体操，数学教学的主要任务是发展学生的思维，促进学生智慧的生成。思维训练是计算教学的核心。本课教学中，我能借助计算教学这个平台，让学生学会学习，重视获取知识的思维过程，注重转化等数学思想方法的渗透，通过知识迁移、尝试练习、估算反思、算理辨析、建立模型、实践应用这一系列步骤锻炼学生的思维习惯。从思维方法的指导入手，着重理解为什么小数加法就不能简单地模仿整数加减法末位对齐的方式，引导学生破旧迎新；加强直观教学，重视学生板演及算理叙述，培养学生的形象思维能力；重视估算以培养学生的直觉思维，加强验算以培养学生良好的计算习惯，细心的计算、规范的书写是学生学习计算的根本，真正落实估算、验算作为计算教学重要环节的要求。应该说这也是设计之初希望呈现的又一个亮点。
4、精心练习设计，联系生活，感受数学的应用价值。
为了使学生顺利进行建构生成，我设计了说一说、算一算、改一改、用一用、赛一赛等练习，使学生经历从实际问题中抽象出数量关系，并运用所学知识解决问题的过程。在练习中贯穿始终的要求是“算得又对又快”，强化估算在计算中的作用，即重视多样化练习，又注重学生计算技能的训练。如说一说中让学生充分比较小数加减法与整数加减法的共同点，在算一算中改编了一道题，17.56-7.56以加强学生对小数性质的理解和应用；改一改中，选择了相同数位不对齐、得数中忘记点小数点、整数部分为“0”的处理等三道题，提醒学生关注小数加减法计算的错误点，以提高计算的正确率；用一用中，精心选择了奥运会射击成绩、神七的飞行高度（恰好上课当晚发射）、射阳至盐城的路线选择等，希望通过解决实际问题进一步培养了学生的数感，增进学生对计算算理的理解，激发学生的民族自豪感。
以上是我在执教本节课时，意图体现的一些想法，可能实施得还不够到位。比如，有一位同学在计算4.75+3.4时，采用了第三种算法，可是通过估算得数大约等于8，所以将5.09改成8.09，因为上课时实物展台出现问题，对这个课堂生成的内容处理得还不够到位。赛一赛中，尽管教师在练习之前已经强调了“又对又快”的要求，但因为是比赛，结果导致学生片面追求速度，而忽略了计算的正确率。这些都需要我在今后的教学实践中，不断完善，不断探究，以提高计算教学的实效和质量。
有理数的减法教学设计 四年级小数加减法教学设计篇九
四年级下册数学95—97页
1、经历探索小数加、减法计算方法的过程，体会小数加减法与整数加减法在算理上的联系，掌握小数加减法的计算方法。
2、进一步增强运用已有知识和经验探索并解决问题的意识，不断体验成功的乐趣。
理解并掌握小数加减法的计算方法。
：理解小数点对齐，也就是相同数位对齐的道理。
：多媒体课件。
：
一、联系生活情境导入
1、师：小数在我们的生活中很常见，老师手中的这两本书大家一定不陌生吧！一本是语文，一本是品德与社会，这两本书的价钱同样是用小数表示的。拿出这两本书来，谁来告诉老师这两本书的价格分别是多少？
（语文：5.69元品德与社会：6.18元）
2、师：根据我们发现的这两本书的价格信息，你能提出什么数学问题呢？
（两本书一共多少元？两本书相差多少元？）
第一个问题用什么方法计算？第二个问题呢？
师：其实，在我们的生活中很多时候都要用到小数的加减，这节课我们就一起来研究小数的加法和减法。（板书课题：小数的加法和减法）
二、尝试计算，构建新知。
1、学生尝试计算。
学生在练习本上计算，先列出横式，再列出竖式。
（指名两位同学到黑板上完成，教师巡视指导。）
师：你是怎样计算的？
学生交流。
师：刚才同学们都谈到了相同数位对齐，满十进一，不够减向前一位借一，这些方法，我们在什么时候用过呢？（整数加减法的时候）
师：那也就是说，计算小数加减法其实是按照——整数加减法的计算方法来计算的。
2、观察算式，发现方法。
师：下面请同学们观察一下这两个题，你认为在计算小数加减法时应该注意什么？（小数点对齐，相同数位对齐）
三、自主编题，内化知识。
1、联系生活，自主编题。
师：昨天，老师走进了一家文具店，看到了这样一些商品信息。
课件出示：书：33.27元彩色笔：9.6元
足球：60.4元跳绳：7.53元
师：你能用这些信息编一道题自己解决吗？把你想到的问题记在心里，把你的解决方案写在纸上，先列出横式，在列出竖式。
2、同桌交流：（1）你提出了什么问题？
（2）你是怎样计算的？
（3）通过这个题的计算，你想提醒大家什么？
3、全班交流。
（1）挑选两位小数减一位小数的题。如：33.27—9.6=
师：刚才这位同学提到了小数点对齐，我们为什么一定要让小数点对齐呢？
（小数点对齐就保证了相同数位对齐。引导学生用小数的意义来解释。）
（2）一位小数减两位小数。如：9.6–7.53=
师：当遇到一位小数减两位小数或位数少的小数减去位数多的小数时，我们可以根据小数的基本性质在小数的末尾补“0”，这样计算起来更方便。
（3）得数是整数。如：9.6+60.4=70.0（元）
师：我们接着看这位同学编的题，一起读出它的结果？70.00元
师：怎样写更简洁呢？（直接写出70元）
师：太棒了，像这种情况，在横式上写结果的时候我们一般要对结果进行化简，体现数学的简洁美。
（4）小结：刚才我们看了这么多同学编的题，那现在你认为我们的小数加减法还应该注意什么呢？
（要对结果进行化简——把小数点末尾的0去掉。）
（5）看来，大家的收获可真不少，那你会计算小数加减法了吗？好，那同桌相互检查一下自己编的题，看有没有什么问题，如果有问题就改正过来。
师：同学们今天的表现非常不错，通过自己编的题了解了小数加减法的计算方法，还明白了方法背后的道理，有了这些理解，相信你一定能够灵活而准确地解决各种不同的问题，就让我们带着这些收获进入我们的闯关游戏当中吧，看大家掌握得怎么样？你们敢挑战吗？
四、巩固练习，拓展提高
1、第一关：定位停车
（1）5.73－0.6=5.13
师：这里有一个小数减法的算式，被减数5.73已经写好了，减数0.6已经在小卡车上准备好了，这辆小卡车开到哪儿停下了合适呢？这样，用你们的声音来控制它，一会儿小卡车开动起来，你觉得该到哪儿停你就喊停。
（2）课件出示12+0.43=
这一次又该停在哪儿呢？怎么了？（开过了）
师：卡车司机犯难了，12没有小数点，该怎么对齐呀？谁来给他出出主意？
在你们的眼里12也有小数点，12的小数点在12的后面。（课件演示12的小数点）是这样吗？那我们让小卡车退回来，这样就可以做加法了，结果是：12.43。
2、第二关：摘取智慧星
下面有三颗智慧星，但要得到智慧星必须正确计算出下面的算式，你有信心闯关并摘取智慧星吗？
7.2–6.45=12.53+4.67=5–0.41=
在自己的练习本上完成。
5–0.41=在列竖式的时候，5改写成5.00可以吗？那为什么不改写成5.0呢？
3、第三关：认识小巨人
师：你们认识他吗？（姚明）你们知道他的身高是多少米吗？（2.26米）
师：这是2008年，北京奥运会入场的画面，他牵着一个小男孩，你们认识他吗？
师：他就是在汶川大地震中背出了两名同学的小英雄林浩，你们知道林浩当年的身高是多少吗？
师：老师给你们一个小提示，你一定能算出来。
拓展：姚明的身高2.26米，林浩站在0.45米的凳子上还比姚明矮0.53米，林浩的身高是多少米？
学生在练习本上完成。
师：林浩的身高是1.28米，他俩的身高虽然相差了很多，但他们都是我们心目中的英雄，都是我们学习的榜样。
四、课堂小结：（3分）
同学们，今天我们一起研究了小数加减法，最令人高兴的是我们是通过自己编的题来研究的，那这节课你有什么收获呢？
有理数的减法教学设计 四年级小数加减法教学设计篇十
1使学生会算一位小数的加减法，并结合生活情境让学生提出问题，能够运用所学知识解决生活中的一些简单的实际问题。
2经历一位小数的加减计算方法的形成过程，体验小数加减法的算理和算法。
3通过让学生试算小数加减法，培养学生的自学能力和尝试精神。
4通过创设生活化的情境，使学生感受到学生与生活的密切联系，培养学生的数学情感和团结合作的良好品质。
使学生学会计算一位小数的加减法，并根据所学知识解决生活中的实际问题。
如何列竖式计算小数加减法？尤其要注意小数点对
多媒体课件、购物单，复习卡片
一、创设情境，生成问题
1、复习
同学们前面我们学习了整数加减法，你能列竖式计算几道吗？
课件出示：91-29 62+28 123-75
学生独立完成后全班交流
让交流的学生说说的计算过程，列竖式计算应注意什么问题？
2、谈话导入
师：同学们谁自己买过东西？都买过什么东西？
引导：谁一次买过两种或两种以上的东西？怎么花的钱？（生自由谈）
过渡：同学们不但会花钱，而且还会算帐，你们真聪明，今天老师想带同学们去数学乐园的商店逛一逛，你们愿意去吗？（愿意）那我们去看看吧！（课件出示文具货架主题图）
二、探索交流，解决问题
1、课件出示，提出问题
师：同学们观察画面，你能说说这幅图的图意吗？（生自由谈）
根据这幅画面你能提出什么问题？我会给每个人一次机会，看看你能不能把握了？
全班交流，师有选择地板书两个问题：
⑴一个转笔刀和一枝铅笔一共多少钱？
⑵有橡皮的铅笔比没橡皮的铅笔贵多少钱？
师：现在我们就来解决这两个问题，不过别着急，其他问题我们一会再来交流。
2、探究算理以及方法
师：同学们，你是怎么解决这个问题的，把你的想法告诉大家好吗？
生：0.8元等于8角，0.6元等于6角，8角+6角等于14角，也就是1元4角，是1.4元。
师评价：太好了，你能联系学过的知识解决问题，很有数学头脑！
生：我是直接用小数计算的，
师：你能把竖式写在黑板上吗？能说说你的想法吗？
学生板演：0.8+0.6＝1.4（元） 1.2-0.6＝0.6（元）
元 角 元 角
0 . 8 1 . 2
+ 0 . 6 － 0 . 6
1 . 4 0 . 6
师在竖式上写上“元”“角”
师再出示问题：一个书包和一格文具盒一共多少钱？
请同学们列竖式计算此题，指名到黑板上板演，同时老师在黑板的一角板演：
根据学生的练习让其他学生交流想法。
3、归纳总结
师引导：像这种加减法，我们就叫做它小数加减法。（板书）
那么在小数加减中，我们应该注意什么呢？（相同数位对齐）
为什么？既然小数计算对齐数位这么重要，那么你有什么对齐小数数位的好窍门吗
生：只要小数点对齐就行了。师及时给予指导与评价。
三、巩固应用，内化提高
1、练习（发购物单）
教师：同学们把自己最喜欢的两种学习用品填入购物单，并计算出一共多少钱？
（教师巡视）
展示学生练习，并自己说一说购物单的内容。
再次引导学生小结：小数加减法与以前所学的加减法在计算上有什么相同的地方？怎样计算小数加法？
2、教师：同学们，当你选好东西到付款处付款后，收银员阿姨会给你一张小票，对不对？这里有一张老师在超市购物的小票，（出示课件超市小票图）你从上面可以看懂哪些信息？
永 辉 超 市
品名 单价 数量 金额
毛笔 2.5元 1 2.5元
书包 25.8元 1 25.8元
橡皮 0.5元 1 0.5元
墨水 3.5元 1 3.5元
总额:32.3元
（学生畅所欲言）
教师：那同学们用我们今天所学到的知识，每人提出一个数学问题，并自己解决。
(展示学生解答的结果，并自己说说所提的问题及解题方法。)
3、生活实践
老师带同学们去公园划船，有一大一小两种船，大船限载100千克，小船限载80千克，4人租用一大一小两只船行吗？该怎样乘船？（出示课件老师带学生去划船的情境）
小明：37.2千克 小林：33.6千克
小红：32.7千克 老师：57.2千克
小组讨论：有几种不同的乘船方案。
四，回顾整理，反思提升
在生活中用到小数的地方还真不少，我想只要我注意观察一定还会发现许多与小数有关的问题。同学们，你们今天又学了哪些与小数有关的知识呢？你有什么收获呢？小数加、减法与以前所学的整数加、减法有什么相同的地方和不同的地方？
板书设计 ：
简单的小数加减法
1、一把小刀和一枝铅笔一共多少钱？
2、有橡皮的铅笔比没橡皮的铅笔贵多少钱？
元 角 元 角
0 . 8 1 . 2
+ 0 . 6 －0 . 6
1 . 4 0 .6
有理数的减法教学设计 四年级小数加减法教学设计篇十一
5以内减法是学生学习减法意义的开始，也是今后进一步学习加减法的基础，起着承前启后的作用。省编义务教材的编写意图是这样的：当学生看图列出算式5—2后，老师问：5—2=？怎样算？然后师生根据前面所学的数的组成的知识，5可以分成2和3，得出5—2=3。相对来说，由于省却了课堂讨论和多次指名的时间，所以课堂练习的时间多了，再经过不同层次的口算练习，达到正确口算的教学目的。但学生在计算时是按老师的方法完成运算，老师向学生提供只有一种可能或一种答案，一题一解，拉着学生按单一的思路进行算法的探索，长期这样训练则容易导致思维僵化，严重束缚了学生的思维，不利于学生思维的发展和创新能力的培养。人教版教材关于5以内减法的教学是另一种形式，当学生列出算式5—2后，老师引导学生得出倒数法，5的组成知识和数数法，虽比省编的教学思路有所发散，但我觉得还是没有完全放开。
以数学课程标准为依据，以建构主义心理学等理论为基础的新编数学教材，教材重视问题的探索性，题材的丰富性和信息呈现形式的多样性，重视问题解决策略的多样化和答案的不唯一性，这些都十分有利于培养学生的创新意识及创新能力。
“5以内减法”是第一册的内容，是学生在学习了５以内的加法的基础上进行教学的，让学生初步理解减法的意义，并能正确进行５以内减法计算。从整体上说，课文没有给出具体详细的算法，教师可以引入自己喜爱的方法，学生也可以发展他们自己的方法，教材这样编排的意图是为了提倡算法的多样化，留给学生选择的自由。所以我是这样进行例题教学的：
当学生看图列出算式5—2后，我问5—2等于几？
学生齐说：5—2等于3
我又问：你是怎样算的？让学生先独立思考，尝试解决问题，学生准备后，再进行小组讨论交流。
学生小组讨论（课堂气氛活跃起来，出现了以下算法），再派代表回答：
甲：看图数数1，2，3
乙：倒数法：4，3
丙：因为5比2大3，所以5—2=3
丁：因为2+3=5，所以5—2=3
戊：因为5可以分成2和3，所以5—2=3
己：5—3=2，所以5—2=3
（看，学生的算法是如此多样，有几种连我备课时都没有想到的。）
然后，老师不点明哪种算法好，或要求学生用那种算法。接下来要求学生有次序地，即不重复、不遗漏地把5以内减法全说出来，并看板书说说发现的规律，最后进行不同层次的练习，达到正确口算５以内减法的教学目的。
但是，这样教学，最后练习时我只进行了一个基本练习，即看算式说得数（开火车口算）和综合游戏：帮小鸽子找家（看算式找得数）。对于新课的学习，我发现个别优生不但已会正确口算，而且也能达到比较熟练的程度，大多数学生会正确口算但不熟练，个别学困生有时还出现算错的现象。而接下去按教材编排又是新课，那么上一节课没有彻底解决拖下来的问题怎么办呢？毫无疑问肯定要到课后去补，要给学生“开小灶”。而学生由于当堂知识没有当堂消化，做起作业来，也肯定质量不高，交上来批改后又要订正，又要“开小灶”，引起恶性循环。
上面片断的教学中，我积极提倡算法的多样化，为学生提供了数学交流的机会，目的是促进学生的数学思维活动，提高学生的数学思维能力。由于提倡算法的多样化，不同的学生有不同的解题策略，他们会运用自己的方法解决问题，会对解决数学问题有深切的体验，从而取得学习数学的经验。这些算法都是学生根据自己已有的基础知识和生活经验思考的结果，每一个不同的算法，就代表了一个创新的意识，从而有效地进行了发散性思维训练。
虽然算法的多样化对于发展学生的独立思考和创造思考的能力确实有很大的帮助，但是我又觉得如果每节课化太多的时间侧重于思维品质的培养，教室里看上去总是热热闹闹，而老师不去管学生的基础知识会不会扎实，基本技能有没有掌握，那么学生应该会做的题目不会做，应该会解决的问题不会解决，各种考试成绩出不来，合格率和优秀率没有达标，成绩太差，在现行素质教育还没有完全或真正替代应试教育的观念下，家长会怎么想？他们会认为学校没有发挥优势，所以我一直在想如何把素质教育和应试教育有机地结合，充分地取长补短？
我认为：
首先，应该端正认识，明确素质教育和应试教育并不是完全对立，不可调和的，两者完全可以有机结合，取长补短。
再者，在平时备课时我努力遵循教材编写的宗旨，使学生体会数学与大自然及人类社会的密切联系，体会数学的价值，增强理解数学和应用数学的信心，初步学会运用数学的思维方式去观察、分析、解决日常生活中的问题，形成勇于创新的科学精神。在具体的教育过程中，以培养、发展、弘扬学生的主体性为根本目的，尽可能增大学生学习的自由度，使学生对知识有一个主动获取，主动发展的内化过程，积极形成一种“问题情境－－－－—建立模型－－－－—解释与应用”的教学模型，即老师创设诸如生活情境、动画情境、游戏情境……。，把学生引入情境中来，使学生意识到问题的存在，从而开动脑筋从数学的角度探求解决问题的方法，还能把所学的知识应用到实际中去，达到学以致用，这样的课堂教学模式有利于学生主观能动性的发挥，有利于学生身心愉悦地发展。
例如，在学习20以内的退位减法时，书中创设了购物的情境，我让同桌二人分别扮演售货员和顾客，商店有15支铅笔，售出9支，还有几支？学生探究算法，有的用破十法，先算15—10，再算5+1；有的用连减法：把9分成5和4，先算15—5，再算10—4；也有把15分成10和5，先算10—9，再算5+1；也有想加算减，还有一根一根地数数法等，方法多样化，人人动脑参与学习过程。接着我出示同类问题，让学生把这种算法应用到同类问题中，学生真正成为了学习的主人，达到了学思结合。
再次，以教材为主线，充分吸取教材的优点，如追求基础知识扎实，基本技能牢固等，撇开它们有时教学思路单一、死板的缺点，所以平时备课时，根据需要把教材的内容补充进去，新授时灵活采用教学方法，新授之后努力提高课堂练习密度，深度与广度。有时，根据内容需要，再上一节练习课，以达到巩固熟练的目的；有时，新课的知识点较多，学生掌握有些困难，就分两教时教学。
或许同仁们会有更好的办好，我只想以自己亲身经历的案例，以期抛砖引玉。
有理数的减法教学设计 四年级小数加减法教学设计篇十二
1、通过自主探究，学生能理解分数加减法的意义与整数加减法意义相同，掌握同分母分数加减法的计算法则，能正确迅速地计算有关习题。
2、利用所学的知识能够解决实际生活中的问题，培养学生知识的应用能力。
3、在探究过程中，培养学生的合作意识，提高学生计算能力，增强学好数学的愿望和信心。
理解分数加、减法的意义，正确计算比较简单的同分母分数加、减法。
正确进行同分母分数加、法计算。
一、创设情境，明确目标
(一)复习导入
1、3/8表示把单位“1”平均分成（）份，表示其中的（）。它的分数单位是（），3/8里面有（）个（）。
2、
（1）7/8的分数单位是（）。
（2）5/9里面有（）个1/9。
（3）4/7是4个（）。
（4）3个1/5是（）。
（5）1里面有（）个1/5，即是（）。
3、约分：6/8=5/10=3/9=6/14=
【设计意图】复习旧知，为探究新知做铺垫。
(二)、新课导入师：同学们，你能分别各写一个同分母分数加法和减法的算式吗？下面请大家在草稿上各写一个，并大胆的猜测一下结果是多少。学生写算式。师板书课题《同分母分数加减法》。
二、导学探究，建立模型
（一）导学探究，解决问题
教学例1：（出示课件）妈妈在家烙了一张大饼。爸爸将这张饼平均分成了8块，爸爸吃了其中3块，妈妈吃了其中1块。
1、导学提示，明确方向
（1）请你提出用分数加减法进行计算的数学问题？
（2）独立列式解答
（3）小组内讨论计算方法，试着总结同分母分数加减法的计算方法。
【设计意图】明确探究内容，提高学生的学习效率。
2、自主学习，解决问题
先独立完成，在小组讨论。
（二）展示交流，建立模型
1、展示汇报，重点释疑
（1）爸爸和妈妈一共吃了多少张饼?3/8+1/8=4/8=1/2(张)
（2）爸爸比妈妈多吃了多少张饼？3/8-1/8=2/8=1/4(张)
（3）还剩多少张饼？1-3/8-1/8=4/8=1/2(张)
【设计意图】数学问题来源于学生，体现出学生是学习的主人，同时提高学生提出问题，解决问题的能力，提高学生自主探究的能力，提高学生的计算能力和认真计算的学习习惯。
2、归纳小结，建立模型
同分母分数加减法的计算方法：同分母分数相加、减，分母不变，只把分母相加、减。
三、练习检测，巩固应用
1、2/9+5/9=2/7+5/7=5/8+1/8=4+1/4=
5/6-1/6=7/9-2/9=7/10-1/10=1-11/30=
说说你是怎样计算的？计算结果要注意什么？
【设计意图】提高学生的计算能力
2、春蕾小学图书馆中各类图书情况如图所示。
（1）社会科学、自然科学和文艺类图书共占图书总量的几分之几？
（2）其他图书占图书总量的几分之几？
【设计意图】运用所学知识解决实际问题，既巩固了知识，又让学生体验到成功的喜悦。同时增强学生分析问题和解决问题的能力，激发学生进一步探索的兴趣。
四、整理回顾，反思提升
通过本节课的学习，你有什么收获？
【设计意图】
通过总结评价，帮助学生梳理知识脉络，反思自己的学习过程，领会学习方法，获得数学学习经验。
3/8+1/8=4/8=1/2(张)答：爸爸和妈妈一共吃了1/2张饼.
3/8-1/8=2/8=1/4(张)答：爸爸比妈妈多吃了1/4张饼.
1-3/8-1/8=4/8=1/2(张)答：还剩1/2张饼
同分母分数加减法的计算方法：同分母分数相加、减，分母不变，只把分母相加、减。
有理数的减法教学设计 四年级小数加减法教学设计篇十三
理解和掌握小数的意义，知道用小数表示十分之几，百分之几，千分之几。
知道用小数表示十分之几，百分之几，千分之几。
会进行十进分数与小数的互化。
一、铺垫练习。
填一填、读一读：
1元=（ ）角1角=（ ）分 1元=（ ）分
1米=（ ）分米 1分米=（ ）厘米 1米=（ ）厘米
二、探究、尝试。
1、自学内容一 做一做，说一说。
0.1元=（ ）角 0.01元=（ ）分 1.11元=（ ）元（ ）角（ ）分
0.1米=（ ）分米 0.01米=（ ）厘米 1.11米=（ ）米（ ）分米（ ）厘米
2、自学内容三 想一想，填一填
把“1”平均分成1000份，其中1份是 ，也可以表示（ ），其中的59份是 ，也可以表示（ ）。
3、归纳：
像0.1、0.23、0.049……这样用来表示（）之几、（）之几、（）之几……叫做小数。
分母是10、100、1000……的分数可以分别用（ ）位小数、（ ）位小数、（ ）位小数……表示。
三、巩固练习。
书本p6第1、2、3、4题。
有理数的减法教学设计 四年级小数加减法教学设计篇十四
1.通过自主探索生活中的情境使学生理解小数加减法的计算算理，掌握竖式计算的方法，并能正确计算，培养学生的运算能力，养成良好的计算习惯。
2.通过计算、比较等活动使学生经历把整数加减法计算经验迁移到小数加减法计算的过程，培养学生运用迁移规律的意识。
3.通过解决实际问题，使学生感受到小数加减法在生活中的广泛应用，培养学生的应用意识，增强学习数学的信心。
教学重点：理解小数加减法的计算算理，掌握竖式计算的方法，并能正确计算。
教学难点：理解“小数点对齐就是相同数位对齐”。
教学课件。
(一)创设情境 引出新知
导入1：师：同学们，你们都喜欢读课外书吗?老师想问一问你们自己去书店购买过课外书吗?在一个星期天，小丽到新华书店来选购自己喜欢的图书。
导入2：【老师知道咱班的同学特别爱读课外书，养成读书的好习惯。小丽和你们一样，也非常喜欢读课外书。在一个星期天，小丽到新华书店来选购自己喜欢的图书。】
从这张图上你能发现哪些数学信息?
预设：
生1：小丽买了两本书，一本是数学家的故事，另一本书童话选;
生2：一本《数学家的故事》，价格是6.45元;另一本是《童话选》，价格是4.29元。
师：根据这些数学信息，你能提出什么数学问题?
(1)小丽买了这两本书，一共要花多少钱?
(2)《数学家的故事》比《童话选》贵多少元?
或者说《童话选》比《数学家的故事》便宜多少元?
师：这两个问题，你认为应该用怎样的方法来解答?
预设：
生1：求 “小丽一共花了多少钱?”用加法计算，可以列示6.45+4.29=
求 “贵多少元?”用减法计算，可以列示6.45-4.29=
师：你能估一估这两个算式的结果吗?
估算很重要，同学们平时一定要具有估算的意识。有时候估算既可以节省时间，又可以帮助我们检查和验算。估算也是一种很好的计算方法。
【设计意图】估算是重要的运算技能，通过估算可以帮助推算出结果的大致范围，进而在精确计算中有效避免出现不合理的错误答案。借估算定精算，实现了估算与精算之间的沟通，培养了学生的计算能力。
那这两个算式的结果应该是多少呢?你想通过以前我们学过的哪些数学知识来解决这些问题?
预设：
生1：元角分的知识
生2：简单的小数加减法的计算方法;
生3：整数加减法的计算方法。
生4：相同数位对齐，从个位加起，哪一位上的数相加满十，就向前一位进一。
生5：相同数位对齐，从个位减起，哪一位上的数不够减，就从它的前一位退一当十，和本位上的数合并在一起，再减。
师：同学们说的非常好，学会知识的迁移和类推，合理运用转化的思想，把新知转化为旧知，用旧知来解决新知是一种非常好的数学学习方法。只要同学们善于思考和发现，通过自己的努力和小组的合作，一定能解决这些问题。下面请同学们打开数学书p72，自学例1。
【设计意图】学生根据提供的信息，按照自己的意愿提出问题，这是一个处理信息的过程;在解决问题的过程中，激活学生已有的数学经验和生活经验，用旧知引新知，为他们的学习指明方向，激发起学生探究知识的欲望。
(二)探究新知
1.学生自学，完成自主学习单。
2、小组交流，教师巡视。
3、学生尝试计算，指名板演，呈现不同的算法。
4、全班交流。你们小组解决了哪个问题?是怎么解决的?
预设：
学生1：
学生2：
学生3：
学生4：
【设计意图】借助学生已有的整数加减法的计算经验，以及在具体情境下对小数的理解，给予学生自主探索的空间和时间，鼓励他们用不同的方法计算，大胆尝试探究，让不同层次的学生都能得到不同的发展。
4、重点思考：“为什么小数点一定要对齐呢?”
预设：
学生1：在学习一位小数加法时，就是把小数点对齐，即相同数位对齐。也就是整数部分相同数位对齐，小数部分的十分位的数要对齐。所以当两个两位小数相加时，百分位上的数也要对齐。
学生2：因为不同的数位表示的含义不同，个位表示几个1，十分位表示几个十分之一，百分位表示几个百分之一。当小数点对齐时，相同数位就对齐了。
学生3：因为只有计数单位相同的两个数才能直接相加，所以要把相同数位对齐，即“小数点对齐”。
师：那该怎样计算呢?然后按照整数加法的计算方法进行计算。计算时，从最低位算起，这道题也就是先从百分位加起，5加9得到14个百分之一，百分位满十要向十分位进一，在百分位上写4;十分位上4加2加1得到7个十分之一，在十分位上写7;最后个位上6加4满10，个位满十要向十位进一，个位上写0，十位上写1。那么6.45+4.29=10.74。
首先列竖式时小数点要对齐，也就是相同的数位要对齐。然后按照整数减法的计算法则进行计算。从最低位算起，这个算式应从百分位减起，5减9不够减，就从十分位退一当十再减，15-9=6，得到6个百分之一，在百分位上写6;十分位上4退1是3，3-2=1，得到1个十分之一，在十分位上写1;最后个位上6-4=2，得到2个一，在个位上写2。那么6.45-4.29=2.16。
【设计意图】引导学生通过分析、比较，找到各方法间的内在联系与不同;同时借助笔算小数加法的经历，通过运用数学语言的交流，逐渐理解“小数点对齐就是相同数位对齐”这一本质，体会到小数点对齐的必要性，培养学生的数学思维能力。
5.比较内化
刚才我们学习了小数加减法。和整数加减法比较，你有什么发现吗?我们一起来比较分析。
预设：
学生1：小数加减法和整数加减法都是要把相同数位对齐。
学生2：小数加减法的计算方法和整数加减法的计算方法相同，都是从最低位算起。
学生3：满十就向前一位进1，哪一位上的数不够减，就从它的前一位退一当十，和本位上的数合并在一起，再减。
学生4：小数加减法的验算方法与整数加减法的验算方法一样，可以交换加数的位置进行验算，也可以用减法验算。
在小数加减法计算过程中，我们应注意什么呢?
1：小数点一定要对齐，也就是相同数位要对齐。
2：整数加减法是从个位对齐，而小数加减法是小数点要对齐。
3：小数点要写在个位的右下角，小数点要写成实心的小圆点。
4：计算结果如果末尾有0，可以根据小数的性质去掉。
【设计意图】通过小数减法与小数加法的对比、小数减法与整数减法的对比，帮助学生理清所学知识间的联系与区别，促进学生在头脑中完善与计算有关的知识网络。
(三)知识运用
1.基础练习
教材第72页，做一做。
计算下面各题，并且验算。
6 .07+4 .89 5 .64-1 .78
【设计意图】巩固小数加减法的笔算方法，培养学生验算的习惯。
2.综合练习
(1)教材第74页第3题。
(四)课堂总结
教师：同学们，通过今天的研究，你有什么收获吗?
预设：
学生1：可以将新知识转化成旧知识。
学生2：计算小数加减法时要把小数点对齐。
学生3：小数加减法的计算方法和整数减法的计算方法相同。
……
这节课我们学习了位数相同的小数加减法。
【设计意图】在回顾与反思中，帮助学生建立良好的认知结构，做到在收获知识的同时积累小数加减法笔算的活动经验，并为后续学习奠定基础。
本节课例是在学生掌握了小数的意义和性质以及整数加减法的基础上来学习的。教学这部分知识，不仅要让学生掌握小数加减法的算理和法则，还要同整数加减法结合起来，让学生从整体上把握加减法的实质。
以下是我对本节课的几点思考：
1、注重与生活的联系。
本课例选择了学生熟悉的感兴趣的素材，以“购买图书情景图”作为计算教学的背景。突出了计算不再是枯燥乏味，不再是为了计算而计算，而是让学生感到计算学习同样是生动、有趣的，使学生在解答用小数计算的实际问题时，理解小数加减法的算理，掌握小数运算的基本方法。通过解决实际问题，使学生感受到小数加减法在生活中的广泛应用，培养学生的应用意识，增强学习数学的信心。
2、以自主合作探究为主，培养学生合作能力及合作意识。
通过自主探索使学生理解小数加减法的计算算理，掌握竖式计算的方法，并能正确计算。在例1的教学中我通过学生提出问题，尝试解决问题、交流各自方法、概括归纳出小数加减法的算理，并能掌握正确的计算方法。整个过程体现“学生主体，教师主导”的互动模式，放手让孩子自己去尝试、自己去探索、去获取知识，最大限度地让学生都能参与到探索新知的过程中，参与知识形成的过程中，在探究算法中使每位学生都有获得成功学习的体验。对于6.45+4.29和6.45-4.29的竖式写法，我先让学生自己试着写，再通过格式对比展示，利用学生出现的问题，紧扣教学重点，引导学生联系已有的知识和经验，开展深入的讨论，在相互启发，相互学习中，学生自主提炼出“小数加减法”的竖式计算方法。
3、注重数学思想的渗透。
课堂中注重培养学生发现问题—提出问题—分析问题——解决问题的能力。注重学生对知识的迁移、类推能力，注重培养学生的思维能力。让学生经历数学学习的过程，体验学习的快乐。通过计算、比较等活动使学生经历把整数加减法计算经验迁移到小数加减法计算的过程，培养学生运用迁移规律的意识。通过“小数点为什么一定要对齐”这一问题引导学生探究。使学生明白“这样就能保证整数部分和整数部分对齐，小数部分和小数部分对齐。当小数点对齐时，相同的数位也就对齐了”。在学生充分的讨论、交流的基础上来体会和感悟，加深学生的理解和记忆。
有理数的减法教学设计 四年级小数加减法教学设计篇十五
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