练习二十三

第五单元图形的运动（三）教材第83页“做一做”O逆时针902教材第85页“练习二十一”1．第一幅图是“”绕底部端点顺时针或逆时针旋转而成；第二幅图是“”绕底部圆圈顺时针或逆时针旋转而成；第三幅图是“”绕它的中心点顺时针或逆时针旋转而成的。

2．顺逆3．逆90 逆904．(2)顺180教材第87页“做一做”右下角的图片先向上平移，绕图片的中心点，逆时针旋转90°，再向左平移到左上角；左下角的图片向上平移到左上角，再向右平移到右上角；左上角的图片先平移到左下角，再绕图片的中心点顺时针旋转90°；右上角的图片向下平移到右下角就还原成右图了。

教材第88页“练习二十二”2．(答案不唯一)第六单元 分数的加法和减法教材第90页“做一做”1.25＋25＝45 67－27＝472.79 1 34 414 23 35 59 1930教材第91～92页“练习二十三”1.12 1 73 35 34 25 13 32 2．0 23 15 37 12 1 23 353.813 37 1517 1 65 454.5．(1)1－(215＋215＋215＋315＋315)＝15(2)215＋215＝415(3)(答案不唯一)四、五年级的学生人数共占几分之几？ 315＋315＝256.89 1011 54 310 12 0 7．(1)311＋211＋511＝1011(2)1－1011＝1118．> < < ＝ ＝ <9.14＋34＝1 1＋14＋34＝23 4－14＝121－14－34＝02 5＋45＋15＝7545－25－15＝157 9＋29＝179＋49＋39＝1494 9－39－19＝039＋49＋29＝11 6＋56＝116＋56＋76＝1367 6－56＝1376－16－56＝16(答案不唯一)10.12－110＝2525＋35＝11－47＝3737＋57＝87(答案不唯一)11.720＋320＝1020＝12(米)教材第93页“做一做”23 245825281340教材第94页“做一做”1.78 1124 512 16 1320 1328 78－38＝12 1328＋14＝572.45－34＝120(kg) 45＋34＝3120(kg) 教材第95～96页“练习二十四”1.124 1318 421 1120 3463 215 512 1835 2．＋ － ＋ ＋ － ＋ － 3.14＋38＋310＝3740 1－3740＝340 4．x ＝928 x ＝1924 x ＝116 x ＝2455．(√) (×)35＋47＝4135(×)710－35＝110(√) 6.112 710 142 1130 156 1772 16 1990 7．还剩下几分之几？ 1－710－120＝14(答案不唯一)9.教材第98页“做一做”1.23 58 712 215 0724 712 1452．113 112 212教材第100～101页“练习二十五”1.1930 928 58 2936 340 215 2．1－14－38＝38(m)这个三角形是等腰三角形。

解决问题（例5）一、学习目标（一）学习内容《义务教育教科书数学》（人教版）一年级上册第97页情境图及第99页练习二十三的第1、3、5、6题。

《解决问题》是“数的运算”这一部分的课程内容。

《课程标准》要求：能运用数及数的运算解决生活中的简单问题。

本节课是人教版数学一年级上册第八单元的第四课时，是在学习了关于前面解决问题的基础上，来学习20以内的解决问题。

从情境图中了解到以图文结合的形式来提供较多的信息，并且在同一情境图中呈现了不同的解决方法，体现了数学与生活的广泛联系。

（二）核心能力“解决问题”这节课，通过经历发现问题和提出问题，运用所学知识解决简单的实际问题的过程，培养学生的应用意识，提高实践能力。

（三）学习目标1.借助情境图，学生能找出解决问题需要的信息，体会两个相关信息和一个问题构成一个数学问题。

2.经历解决问题的过程中，学生能运用不同的方法解决同一个实际问题。

（四）学习重点会看图找到有用的信息解决问题。

（五）教学难点根据信息和问题之间的关系，选择合适的信息并列式计算。

（六）配套资源实施资源：《解决问题》名师课件二、学习设计（一）课前设计预习任务（1）预习课本第97页，说一说图中有什么信息，哪些信息是有关的？（2）要求一共有多少人？用（）法计算。

练习：（1）左边盘子里有5个苹果，右边盘子里有8个，一共有（）个苹果。

（2）小明折了6颗星星，小丽折了7颗，一共折了（）颗星星。

（二）课堂设计1.复习导入师：说一说图中告诉我们什么？要解决的问题是什么？并解答。

2.问题探究师：马上要到元旦了，小朋友们要开联欢会了，一一班的小朋友在排练节目呢，你们看！（课件出示主题图。

表演的同学一会儿按前后分两排分开，一会儿按男生、女生分开）仔细观察这幅图，你看到了什么数学信息？同桌相互说一说。

【设计意图：通过播放课件小朋友们联欢会的景象，学生兴趣大增，提高学生的学习兴趣。

】（1）发现问题师：根据这些信息，你能提出什么数学问题？师：有哪些信息跟这个问题有关系连起来说一说。

高考英语专题练习（二十三）语法填空＋阅读理解＋任务型阅读Ⅱ．阅读理解（2014·黑龙江鹤岗一中模拟）People tend to have one of three beliefs about the meaning of work and which category you fall into largely depends on your parents, according to the new research from the University of Michigan.Workers who are job-oriented are those just trying to make a living who much prefer the activities they pursue outside of the office. Career-oriented adults — your typical “workaholic” — value the social status and reputation that comes with professional achievement, and gain much of their identity from their jobs. Calling-oriented people do work that they are passionate about because they want to have a positive impact on the world.In the first empirical study into how these orientations originate, researchers found that how teenagers view their parents' work ethic is central to the development of their own work attitudes.It's not a straightforward transfer of values. People who perceive their father to have a strong career-orientation are more likely to be career-oriented themselves, but career-determined mothers have no effect on their kids' work orientation. The researchers attributed this to generational gender norms. When the study's participants were teenagers, mostly in the 1980s, men were more commonly employed outside of the home and were more likely than women to hold “career” jobs with opportunity for advancement.Mothers do have a notable effect on whether children have a job-orientation mentality. Teenagers who are close to their mothers are less likely to view work as just a job when they grow up, probably because they've been raised to value social, rather than instrumental, life experiences.Having both parents display the same work ethic has an amplified influence, but only in the case of calling-oriented children. As our society favors money and professional achievement, a child with two calling-oriented parents is more likely to have the confidence to ignore these social pressures and pursue his dreams.Children can affect their parents' work ethic, too. Allowing people to bring their children into the office has been shown to improve efficiency and productivity—and could help raise that next generation of career-oriented workers. 1．If you are proud of being a teacher, and you are enthusiastic about your job, you belong to ________.A．the job-oriented groupB．the career-oriented groupC．the workaholic groupD．the calling-oriented group2．Which of the following statements is TRUE according to the passage?A．Children valuing their parents' career-orientation will be career-oriented.B．Fathers have a greater influence than mothers on teenagers' attitude towards jobs.C．Calling-oriented mothers have little effect on their children's work orientation.D．Children's attitudes towards jobs aren't related to parents'.3．What does the underlined word “amplified” in Paragraph 6mean?A．Enough.B．Increased.C．Decreased.D．Strong.4．What is the attitude of the child with two calling-oriented parents towards the social pressure?A．He takes no notice of it.B．He thinks too highly of it.C．He looks on it as a difficulty.D．He considers it confusing.Ⅲ．任务型阅读（2014·银川质检） 1 It makes people suffer a lot from it. Why can't they find a cure for the common cold? The answer is easy. There are actually hundreds of kinds of cold viruses out there. You never know which one you will get. 2When a virus attacks your body, your body works hard to get rid of it. 3 You feel terrible because you can't breathe well, but your body is actually eating the virus. Your temperature goes up and you get a fever, but the heat of your body is killing the virus. You also have a runny nose to stop the virus from getting into your cells. You may feel very uncomfortable, but actually your wonderful body is doing everything it can to kill the cold.4 In China and some other countries, for example, some people might eat chicken soup to make themselves feel better. Some people take hot baths and drink warm liquids. Other people take medicine to stop various symptoms of colds.There is one interesting thing to note—some scientists say taking medicine when you have a cold is actually bad for you. The virus stays in your body longer because your body doesn't have a way to fight it and kill it. 5 There is a joke, however, on taking medicine when you have a cold. It goes like this: it takes about one week to get over a cold if you don't take medicine, but it takes only seven days to get over a cold if you take medicine. So you should trust the function of your body.A．Therefore, there isn't a cure for each one.B．Bodies can indeed do an amazing job on their own.C．How much do you know about the various viruses in the world?D．Blood rushes to your nose and causes a block in it.E．Different people do different things to deal with colds.F．The first thing you need to come up with is an idea for your cold.G．It is easy for many people to catch a cold in spring or fall.语法填空＋阅读理解＋任务型阅读答案Ⅰ．A1．for2．to buy3．was waiting4．how5．amazement 6．her7．when/as8．the9．best10．whichB1．if/whether2．to3．collecting/to collect4．Out5．Interested 6．they7．have been collecting8．roughly / appropriately 9．which10．countriesⅡ．1~4．DBBAⅢ．1～5．GADEB语法填空＋阅读理解＋任务型阅读解析Ⅰ．A1．解析:for考查介词.由语境可知,此处应用for表示目的.我在购买我做志愿者工作所需的物品.2．解析:to buy考查非谓语动词.此处为不定式作目的状语.3．解析:was waiting考查时态.由语境可知,此处描述的是当时正在发生的事,所以用过去进行时.4．解析:how考查宾语从句的引导词.由语境判断应用how.此处表示“挨着我的那位女士接近我,想知道我将如何吃掉我买的这一大盒豆腐”.5．解析:amazement考查词性转换.此处是“to one's＋名词”结构,故空格处应用amaze的名词形式,to my amazement“使我大为惊奇的是”.6．解析:her考查代词.由设空特点看,此处需要限定词,再结合语境“she responded that she felt good. . . ”可推知应用her.7．解析:when/as考查从属连词.此处表示“当她的父母作为难民来到这个国家时”.8．解析:the考查冠词.由语境可知,此处特指当前这个付款的机会,因此用定冠词.9．解析:best考查形容词的最高级.由后面表示范围的定语从句“I had ever received for my voluntary work”可知此处应用最高级形式.10．解析:which考查定语从句的关系词.此处which指代“my voluntary work”,并在定语从句中作主语.B1．解析:if/whether考查宾语从句的引导词.此处表示我想知道你是否可以告诉我一些关于你集邮的事情,故应填if/whether“是否”.2．解析:to考查动词不定式的省略.此处完整的句子应是“I'd be pleased to tell you something about my stamp-collecting. ”,动词不定式所表示的内容与上面相同,动词不定式省略到to.3．解析:collecting/to collect考查非谓语动词.start后接动词时要用动名词或者不定式.4．解析:out考查副词.work out表“计算,统计”之意,为固定短语,符合语境.5．解析:interested考查词性转换.be interested in表“对……感兴趣”之意,为固定搭配,符合语境.6．解析:they考查代词.此处指代“my first packet of stamps”,因此用they来代替.7．解析:have been collecting考查时态.依据时间状语可知,Gibbon这些年一直都在集邮,因此用现在完成进行时,表示动作的持续性.8．解析:roughly/appropriately考查语境.此处表示邮票的大约数目,因此用roughly/appropriately.9．解析:which考查定语从句的关系词.这里是引导非限制性定语从句,关系词代指the Penny Black,且在从句中作主语,因此用which.10．解析:countries考查名词单复数.此处country是可数名词,被these修饰,要用复数形式.Ⅰ．1．解析:选D推理判断题.从第二段最后一句“Calling-oriented people do work that they are passionate aboutbecause they want to have a positive impact on the world. ”特别是“passionate”一词可知答案.2．解析:选B推理判断题.从第四段中的“People who perceive their father to have a strong career-orientation are more likely to be career-oriented themselves, but. . . work orientation. ”可知答案.3．解析:选B词义猜测题.从画线词后面的“a child with two calling-oriented parents is more likely to. . . ”可知,amplified意为“增加的”.4．解析:选A细节理解题.从第六段中的“a child with two calling-oriented parents is more likely to have the confidence to ignore these social pressures and pursue his dreams. ”可知答案.。

10、略第67页做一做答案1、∠2=15º2、每个小三角形的内角和都是180º。

第68页做一做答案180º×(6-2) =720º提示：六边形可以分成4个三角形。

练习十六答案1、左图：180º-65º-37º=78º中图：90º-30º=60º或180º-90º-30º=60º右图：180º-20º-25º=135º2、(1)180º÷3=60º三个角都是60º。

(2) (180º-96º)÷2=42º三个角分别是96º、42º、42º。

(3) 90º-40º=50º三个角分别是90º、40º、50º。

3、1800-700×2=4004、发现：n边形都可以分成（n-2）个三角形，所以n边形的内角和=180º×(n-2)。

5、略6、提示：(1)另外两个角的度数之和一定是90º，即如果一个角是10º，那么另一个角就是80º，如果一个角是20º，那么另一个角是70º……(2)假设另一条边是acm，则a+3>4⇒a>1，3+4>a⇒a<7，所以另一条边一定比1cm长，比7cm短。

可能是2cm、3cm、4cm、5cm……7、1个 3个6个 10个……规律略第72页做一做答案1、3. 54 17.2 10.963.86 6.4 8. 162、(1)29. 8-22. 7=7. l(kg)(2)27. 5-24. 6=2. 9(kg)9岁比8岁增加得最多，增加了2. 9kg第73页做一做答案练习十七答案1、3. 4 9. 4 13. 7 0. 540. 7 1. 9 3. 3 0. 632、4.12 28.3 17.0425.6 4.68 4.263、0.95-0.35=0.6(kg)4、163.54元 159.26元 162.80元160.00元 322.80元5、10.32 16.08 20.243.08 44.3 0.456、7、原式=5.62元+3.09元=8.71元原式=1.03t+0.98t=2.Olt原式=4.35m+5.7m=10.05m原式=10kg-4.8kg=5.2kg原式=4.8km-3.05km=l.75km原式=6km-2.86km=3.14km8、75. 80+45. 50=21. 30(元) 75. 80+ 58. 00=38.00(元)92. 50+45. 50=33. 80(元)92. 50+58. 00=50. 50(元)9、0. 12m O.5lm O.87m 5.12m 8. 36m O．3秒10、(1)1.0 1.2(2)1. 31 1.36(3)4. 375 4.378(4)7. 877 7.872第76页做一做答案1、3. 24 3.6 117.32、38.5+4.8=43.3（元）50-43.3=6.7（元）练习十八答案1、9.1 8.1 0. 820.5 3.6 2.32、27. 07 17. 21 22. 2712. 41 43. 29 33. 433、39.36 9.69 24.475.2 36.39 8.224、分析：先求出海洋面积，再减去陆地面积。

课时作业(二十三) 空间两点间的距离公式[练基础]1．点P (2,3,4)到x 轴的距离是( ) A.13 B ．2 5C ．5 D.292．在空间直角坐标系中，点P (－1，－2，－3)到平面xOz 的距离是( )A ．1B ．2C ．3 D.143．设点B 是点A (2，－3,5)关于xOy 平面的对称点，则A 、B 两点间距离为( )A ．10 B.10C.38 D ．384．在长方体ABCD -A 1B 1C 1D 1中，若D (0,0,0)，A (4,0,0)，B (4,2,0)，A 1(4,0,3)，则对角线AC 1的长为( )A ．9 B.29C ．5D ．2 65．已知点A (3,3,1)，B (1,0,5)，C (0,1,0)，则AB 的中点M 到点C 的距离|CM |等于( ) A.534 B.532C.532D.1326．在空间直角坐标系中，一定点到三个坐标平面的距离都是2，那么该定点到原点的距离是( )A. 6 B ．2 3C. 3D.2637．在空间直角坐标系中，设A (1,3,0)，B (－3,6,12)，则|AB |＝________.8．点P (1,2,3)与Q (1，－1，m )两点间的距离为13，则m ＝________.9．在Rt △ABC 中，∠BAC ＝90°，A (2,1,1)，B (1,1,2)，C (x,0,1)，则x ＝________.10．已知A (3,3,1)，B (1,0,5)，求：(1)线段AB 的中点坐标及AB 的长度；(2)到A ，B 两点的距离相等的点P (x ，y ，z )的坐标满足的条件．[提能力]11．[多选题]在空间直角坐标系中，以点A (4,1,9)，B (10，－1,6)，C (x,4,3)为顶点的△ABC 是以BC 为底边的等腰三角形，则实数x 的值为( )A ．－2B ．2C ．6D ．－612．一束光线自点P (1,1,1)发出，遇到平面xOy 被反射，到达点Q (3,3,6)被吸收，那么光所走的路程是()A.37B.47C.33D.5713．已知空间直角坐标系中点P(1,2,3)，且点Q在z轴上，则使|PQ|最小的点Q的坐标为()A．(0,0,1) B．(0,1,0)C．(0,0,2) D．(0,0,3)14．若A(1，－2,11)，B(4,2,3)，C(6，－1,4)为三角形的三个顶点，则△ABC的形状是________.15．点P在xOy平面内的直线3x－y＋6＝0上，点P到点M(2a,2a＋5，a＋2)的距离最小，求点P的坐标．[培优生]16．在四面体P-ABC中，P A，PB，PC两两垂直，若|P A|＝|PB|＝|PC|＝a，求点P到平面ABC的距离．。