本單元主要是學(xué)習(xí)情態(tài)動詞can的肯定句、否定句、一般疑問句,肯定與否定回答,以及特殊疑問句的構(gòu)成和用法;復(fù)習(xí)what弓!導(dǎo)的特殊疑問句。本單元主要圍繞“加人俱樂部,談?wù)撟约旱哪芰Α边@一話題,設(shè)計了三個任務(wù)型活動:任務(wù)一是:自己的才藝表演,學(xué)習(xí)情態(tài)動詞can的用法;任務(wù)二是:自己建立俱樂部,運用情態(tài)動詞can談?wù)撟约涸谀骋环矫娴哪芰Α⑾埠煤鸵庠?;任?wù)三是:我能成功,主要是復(fù)習(xí)鞏固談?wù)摳髯缘膼酆煤吞亻L的方法。單元知識系統(tǒng)(樹)Can you/he/she/you dance? 一Yes,I/he/she/we can./No,I/he/she/we can’t.Can Bill play the guitar?一Yes,he can,but he can’t sing.單元總體目標(biāo)通過學(xué)習(xí)情態(tài)動詞can的用法,使學(xué)生能夠表達(dá)自己在某一方面所具備的才能;能夠談?wù)撟约旱南埠门c意愿;能夠為自己成立的各種俱樂部制作海報;會寫招聘廣告。單元重難點一覽重點 難點I.復(fù)習(xí)詞匯:can,play,want2.詞匯:guitar, dance, swim,sing, chess, speak, drum,trumpet,violin,play the guitar3.句型:Can you/he/she/you dance?Yes,I/he/she/we can./No,I/he/she/we can’t.Can Bill play the guitar?
在這一單元中,學(xué)生要學(xué)會就有關(guān)人與物之間所屬關(guān)系進(jìn)行問答的句子。本單元大量引入有關(guān)運動的名詞,要求學(xué)生彼此詢問有無此類物品,并做出相應(yīng)的回答。 同時學(xué)習(xí)表示建議的句型Let’s運動的形容詞。 本單元所選用的話題來自學(xué)生所喜歡的生活片段,在教學(xué)中生生交流、師生交流會更融洽,會促進(jìn)師生彼此間的了解,成功的教學(xué)還會讓部分學(xué)生養(yǎng)成良好的運動習(xí)慣和收藏習(xí)慣。 教學(xué)目標(biāo) 1) 語言知識:A.在詢問對方是否有某物的對話中學(xué)會使用do和does引導(dǎo)的一般疑問句; B. 學(xué)會使用描述性的形容詞來評價事物; C. 學(xué)會在對話中使用名詞復(fù)數(shù); D. 學(xué)會用祈使句來向?qū)Ψ教岢鼋ㄗh. 2) 語言技能:A. 學(xué)會用祈使句詢問某人是否有某物; B. 學(xué)會向他人提出建議的句子. 3) 學(xué)習(xí)策略:A.通過與同學(xué)討論,做出猜測;
討論喜歡的影視類型及理由:在看過一部影視作品后,大家總是喜歡在一起談?wù)撚耙暤闹饕獌?nèi)容、主要情節(jié)、主要演員主題歌曲、主題音樂等,互相介紹自己對該影視的看法。教師可以組織一次活動,分組討論學(xué)生喜歡看什么類型的電影,并說明喜歡的理由。運用I like…I don’t like…Because it is…等語言結(jié)構(gòu);然后每個組選派一名代表向全班學(xué)生闡述本組組員喜歡觀看的電影類型;最后匯總,總結(jié)出全班同學(xué)最喜歡觀看哪一種類型的電影。如果有可能,根據(jù)學(xué)生的選擇放一部(一段)這種類型的影視節(jié)目。通過學(xué)生的討論、調(diào)查,使他們在完成任務(wù)的過程中學(xué)會詢問和陳述自己或別人在影視方面的喜好及理由,更好地鞏固所學(xué)內(nèi)容。Self Check教學(xué)內(nèi)容Self Check(教材P58)教學(xué)目標(biāo)知識與能力復(fù)習(xí)詞匯go,movie,action,comedy,documentary,thriller,and,but,scary,funny, sad,exciting;引導(dǎo)學(xué)生復(fù)習(xí)、鞏固“制訂計劃和打算并談?wù)撓埠煤推珢邸钡哪繕?biāo)語言。
本單元主要學(xué)習(xí)一周中星期一到星期天的表達(dá)方式;掌握學(xué)科的表達(dá);學(xué)習(xí)用because和表示品質(zhì)的形容詞表示理由;學(xué)習(xí)what,why,who引導(dǎo)的特殊疑問句。本單元圍繞“談?wù)撟约核矚g的學(xué)科”這一話題,設(shè)計了三個任務(wù)型活動:任務(wù)一是:談?wù)撟约核矚g的學(xué)科,學(xué)習(xí)what引導(dǎo)的特殊疑問句和學(xué)科的表達(dá);任務(wù)二是:一分鐘演講,讓學(xué)生介紹自己喜歡某一學(xué)科的理由,學(xué)習(xí)why等特殊疑問句;任務(wù)三是:寫信,鞏固和延伸所學(xué)知識,掌握星期的表達(dá)方式。單元知識系統(tǒng)(樹)What’s your/his/her favorite subject? My/His/Her favorite subject is English.Why do you like math. Because it’s interesting.Why does he/she like art? Because it’s fun.When do you have math? I have math 0n Monday,Wednesday and Friday.What’s Ken’s favorite subject? Science.單元總體目標(biāo)通過本單元的學(xué)習(xí)使學(xué)生學(xué)會談?wù)撟约合埠玫膶W(xué)科或自己喜好的其它事情并給出理由;學(xué)會說出一周的七天;學(xué)會合理地安排自己的作息時間。
知識與能力復(fù)習(xí)詞匯time,morning,breakfast,get up,g0 t0 bed,homework,clock,afternoon,lunch,run,watch TV,evening,dinner,eat,usually,o’clock,thirty,fifteen,take a shower,go t0 school等;引導(dǎo)學(xué)生復(fù)習(xí)、鞏固“詢問和談?wù)摃r間”的目標(biāo)語言并運用所學(xué)知識安排自己的學(xué)習(xí)和課外活動。過程與方法運用Summarizing,Classifying和Comparing的學(xué)習(xí)策略。在復(fù)習(xí)教學(xué)中,運用聽寫、提問、對話演練與調(diào)查活動,促使學(xué)生不斷地使用所學(xué)內(nèi)容,從而提高他們靈活運用知識的能力。情感態(tài)度價值觀本部分的主要內(nèi)容是復(fù)習(xí)“日常作息時間”的詢問和表達(dá)。通過互相詢問或談?wù)撟约夯驅(qū)Ψ降淖飨r間安排和活動計劃,培養(yǎng)學(xué)生良好的作息習(xí)慣和守時習(xí)慣。教學(xué)重、難點及教學(xué)突破重點復(fù)習(xí)詞匯time,morning,breakfast,get up,g0 to bed,homework,clock,afternoon,lunch,run,watch TV,evening,dinner,eat,usually,o’clock,thirty,fifteen,take a shower,go to school等;引導(dǎo)學(xué)生復(fù)習(xí)、鞏固“詢問和談?wù)摃r間”的目標(biāo)語言。
Step 3 (3b)First, tell the students when we talk about our future plans, we often use: I’m+verb+ing When we talk about what we must do, we use have to. Ask the students to fill in the blanks in 3b. The answers are: shopping, go to see, a test, I’m going, my family. Step 4 (3c)Let the students write an e-mail message to a friend. Say why you can’t visit next. Before the exercise, ask the students to give some possible answers and write them on the blackboard. So the students will feel easy to finish the writing exercise. After they finish it, Let them to correct it in groups first. Each group chooses theirs best one to read in front of the whole class. Step 5 ( planning a party )First read the conversation in the box together. Then ask the students to turn to page 88.Write down everything you have to do next week. Write in all the things you have to do . Ask the students to look at the list. Ask them “What day are you free?” This is when you can have your party. Step 6 (Self check 1 )Let the students to fill in the blanks with the words given. Change the forms of the words if possible. Then make their own sentences. The answers are: visit, playing, have to, study, comeStep 7 (Self check 2)Imagine you are Marie. Read the information and look at your schedule. Write replies to the invitation.
1. First, ... then, ... next, ... finally, ...首先,……然后,……接著,……最后,……這是英語中表達(dá)做某事的步驟的一種說法。如果步驟較多,還可以說:first-next-after that-later on-finally/at last通常你會聽到說英語國家的人在說 first, next, then, finally 和后面的內(nèi)容時,他們會做一些停頓。這樣就能提前告訴聽者接下來講的是一系列的步驟。這一點在朗讀和聽力中應(yīng)特別注意。2. how many, how much均為疑問詞,同是“多少”,但用法不同。請看:how many修飾可數(shù)名詞復(fù)數(shù),how much修飾不可數(shù)名詞。但在用法上,同學(xué)們常犯如下錯誤:1) [誤] How many are there bananas on the table?[正] How many bananas are there on the table?[析] how many, how much 中的many,much是形容詞,常修飾名詞作定語,故后面跟名詞。2) [誤]How much tea are there on the table?[正]How much tea is there on the table?[析] how much修飾不可數(shù)名詞時,謂語動詞用單數(shù)。how many與how much的區(qū)別可簡記為:前how many:問“多少”,復(fù)數(shù)名詞后面跑;how much問“多少”,不可數(shù)名詞單數(shù)好。前者答語用基數(shù)詞,后者答語用數(shù)量關(guān)系。
一、 教學(xué)內(nèi)容Section A 1a----1c二、 教學(xué)目標(biāo)1.學(xué)習(xí)詞匯do the dishes, make the bed, take out the trash, fold the clothes, do the laundry, sweep the floor, clean the living room.2.句型 Could you please clean your room? Yes, sure.三、 教學(xué)準(zhǔn)備 學(xué)生預(yù)習(xí)本單元所有的詞匯多媒體課件 活動表 獎品四、 教學(xué)過程Pre-task1. Warming upEnjoy ourselves. Watch cartoon Cinderella. 看動畫片段《灰姑娘》導(dǎo)如入本課話題和新詞匯“chores”美麗善良的鬼姑娘因繼母的嫉妒,每天得做所有的家務(wù)。片段的主題使學(xué)生聯(lián)想到本課的話題。2. learn new words and phrasesLook! What is she / he dong? 看圖學(xué)習(xí)動詞詞組do chores, do the dishes, make the bed, take out the trash, fold the clothes, do the laundry, clean the living room.3. Guessing game.What is she doing ? 4. Pair work. 1a, Do you do these things at home? Write “Y” for “yes” and “N” for “no”.5. Listening . 1b , Peter’s chores or Mom’s chores?理解目標(biāo)語Could you please clean your room? Yes, sure.Write “M” for Mom’s chores, “P” for Peter’s chores in the chart.6. PairworkLook at the picture,Ask your partner to do the chores that you see. 7. Interview Who is the most able at home? 1) What chores do you do at home? How often do you do the chores? Work in four, interview each of the students in the group, fill in the chart.
Step Ⅶ Role play ( Work on 1b)1. First ask two students to read the dialogue to the class.Sa: How do you get to school?Sb: Well, I ride my bike to the subway station. Then I take the subway.2. Now work with a partner.Suppose you use two kinds of transportation to get to school \Hangzhou\Beijing... (bus, train, subway, walking, bike, etc.) Tell how you get there. You may use the phrases in 1a.3. Then ask different pairs of students to present their conversations to the class.Step ⅧListening1. Work on 2a(1) First ask students to read the list of information that Thomas wants to know.…where Nina lives.…h(huán)ow far from school she lives.…h(huán)ow long it takes to get to school.…h(huán)ow she gets to school.…what she thinks of the transportation.(2) Tell students what transportation and bus stop mean.bus stop 汽車站 transportation n. 運送;運輸Then tell students we'll hear a recording. Please put a checkmark in front of each thing that Thomas wants to know.(3) Now play the recording for students.( Have students pay attention to the sample answer.) (4) Then correct the answers.
Teaching goals : 1. Words & phrases: babysit ,get back , fishing , rent , think about , decide(on) , tourist etc. 2. How to talk about future plans . 3. 現(xiàn)在進(jìn)行時表示將來計劃或行動. 4. 特殊疑問句(where , when , how long引導(dǎo)) Important and difficult points : Drills :What are you doing for vacation ? I’m watching TV . When are you going ? I’m going … . How long are you staying ? We’re staying for five days . Teaching aids : cards and a tape ,a large wall calendar . Period 1 Teaching procedures : Step 1Leading in1. Free talk . 2. Put up the wall calendar . T: I’m staying home on Saturday (pointing to next Saturday ).Ss repeat . Ss: I’m staying home on Saturday . T: OK. Today we’ll learn how to talk about future plans. Step 2Pre-task SB Page 13 , 1a . 1. Look at the picture carefully and tell what you see in the picture . 2. Write the activities from the pictures in the box and add some more . 3. Practice reading . Step 3While-task1. Using the activities we write in 1a to make conversations .For example :What are you doing for vacation ? I’m visiting my uncle . 2. Pairwork .Practice in pairs . 3. 用第三人稱練習(xí)對話.
教學(xué)目標(biāo)1.知識目標(biāo):(1)學(xué)習(xí)What are you going to be when you grow up?/How are you going to do that?句式。(2)學(xué)會用英語描述有關(guān)職業(yè)的表達(dá)法。2.能力目標(biāo):(1)能夠談?wù)摓閷崿F(xiàn)理想所做出的打算和安排。(2)能夠談?wù)撐磥碜约号c他人理想的職業(yè)及原因。(3)能用英語描述課余時間的活動安排,最終具備表達(dá)綜合信息的能力。3.情感目標(biāo):新學(xué)期到來之際,讓他們在學(xué)習(xí)、體育、飲食、特長、讀書等方面制定計劃,教育學(xué)生合理安排自己的課外生活,思考自己的理想職業(yè)及適合自己的職業(yè)。教學(xué)重點、難點本單元的重點為“be going to”表將來,want to be, what,where, when,how引導(dǎo)的特殊疑問句。難點是語言目標(biāo)的實現(xiàn)。教材分析本單元以I am going to be a basketball player為話題,共設(shè)計了三部分的內(nèi)容:一、Section A該部分有4個模塊。第一模塊圍繞Do you think these jobs are interesting?這一話題展開思維(1a)、聽力(1b)、口語(1c)訓(xùn)練;
1 交通工具的比較此活動為小組活動。學(xué)生通過討論找出到達(dá)某一城市可乘坐的各種交通工具,并選擇最佳出行方式。Teacher:We’re going to Shanghai. How many ways can we use to get there? Yes, there are four ways: by bus, by plane, by train, by ship. Please discuss how you are going to get there.操作建議:(1)學(xué)生以小組為單位展開活動,談?wù)摫窘M所選擇的交通工具。(2)各組選代表向全班匯報,闡述本組所選擇的交通工具的利和弊。完成任務(wù)所需要的語言結(jié)構(gòu):We can go there by ship. It’s more comfortable and cheaper than any other transportation.We can go there by bus. It’s cheaper but it takes longer time.2 哪個城市更合適?此活動具有挑戰(zhàn)性。假設(shè)中國要舉行2014年世界杯足球賽,分別從歷史,人文,天氣等方面對各城市(北京,大連,上海,昆明)進(jìn)行比較,選擇最佳舉辦城市。T: Imagine China is holding the 2014 FIFA World Cup. Which city do you think is the best for the World Cup, Beijing, Dalian, Shanghai or Kunming? Let’s work in groups. If you choose Beijing, please join the Team Red. If you chose Dalian, please join the Team White. If you choose Shanghai, please join the Team Blue. If you choose Kunming, please join the Team Green. Please show us its advantages. Then let’s see which team will win.
She shouldn’t go to the party tonight.Step7. TaskT: You know, there are lots of problems in our life. If you are a doctor, please tell us how to solve the problem. I will divide you into 9 groups. Please work in groups. And then choose one of you to report your ideas.The following are the problems:I have a toothache.I am hungry. I have a sore throat.I am stressed out. I have a sore back.I am tired. I can’t sleep.I have a cold. I have a headache.Report: If you have a headache, you should go to bed early. You should see the doctor. You should eat some medicine. You shouldn’t wash your face with cold water.You shouldn’t sleep late.You shouldn’t swim.…..T encourages the students to give advice as much as possible.Homework:1. Chose one of the problems, and write down your advice2. Copy the new words這一步是用于熱身的,同時也可以讓他們復(fù)習(xí)一部分的表示人體部位的單詞,擴充知識.學(xué)習(xí)語言的過程也是一個不斷積累的過程,復(fù)習(xí)舊知識,增添新知識.通過小游戲,強化學(xué)生對Does she/he have…這個句子的運用能力.通過復(fù)習(xí),自然的引到下面新知識的學(xué)習(xí)。充分利用表格,由句子到對話,再到文章,讓學(xué)生循序漸進(jìn). 提高學(xué)生的綜合語言運用能力,運用以前學(xué)過的知識來解決身邊的問題.Period 5 (Section B 3a—3c, selfcheck)教學(xué)內(nèi)容與分析:
教學(xué)目標(biāo): 1. Express preferences2. Talk about one’s likes and dislikes and the reasons3. Learn to express one’s opinions 4. Learn to write a reply 語言功能: 1) Talk about one’s preferences, using t he relative clause2) Talk about people’s likes and dislikes and the reasons3) Talk about opinions語言結(jié)構(gòu): Relative clauses with that and who語言目標(biāo):What kind of music do you like?I like music that I can sing along with.I love singers who write their own music.We prefer music that has great lyric.重點詞匯及短語:heart, photography, interest, class, whatever, miss, okay, expect, sweet, taste, itself, laboratory, cancer, increase, biscuit, main, care, prefer… to…, remind somebody of …, dance to, sing along with, be sure to, interest somebody, make somebody adj., to be honest, suit somebody, on display, catch up教學(xué)重難點:What do other people think of the different kinds of things? How to express one’s opinions? 學(xué)習(xí)方式:討論,合作學(xué)習(xí)情感目標(biāo):通過本單元的學(xué)習(xí),能提高學(xué)生的藝術(shù)鑒賞能力和審美情趣,并引導(dǎo)學(xué)生養(yǎng)成健康的飲食習(xí)慣。課時安排5課時第一課時:Section A: 1a-2c第二課時:Section A : 3a-4第三課時:Section B:1-2c, Self check2第四課時:Section B: 3a-4, Self check1第五課時:Self check ReadingI like music that I can dance to.
內(nèi)容提示1.本單元主要內(nèi)容是學(xué)會used to結(jié)構(gòu)。Used to +動詞原形表示過去經(jīng)常、以前常常,只用于過去式中,用來表示現(xiàn)在已不存在的習(xí)慣或狀態(tài)。例如:They used to play football together.他們過去常在一起蹋足球。(現(xiàn)在不在一起踢了)2.used to的疑問形式和否定形式為Did you use to…?和I didn’t use to… 也可以用Used you to…?和I used not to…但現(xiàn)在多使用前者。例如:Did you used to swim in the river? 你過去常在河里游泳嗎?I didn’t use to play the piano. 我以前并不經(jīng)常彈鋼琴。教學(xué)目標(biāo)一、學(xué)習(xí)目標(biāo)(Language Goal) 1.學(xué)會陳述自己過去常做的事情。2.學(xué)會陳述自己過去的愛好等。3.能夠表達(dá)自己現(xiàn)在和過去在外表、性格、娛樂等方面的變化。4.能夠表達(dá)朋友、家人等現(xiàn)在和過去的變化。二、語言結(jié)構(gòu)(Language Structures) 1.I used to be short when I was young. 我年輕時個子很矮。 2. —Did you use to have straight hair? 你過去是直發(fā)嗎?—Yes, I did. 是的。 3. —Did you use to play the piano? 你過去彈鋼琴嗎?—No, I didn’t. 不,我不彈。 4.I used to be afraid of dark. 我過去害怕黑暗。 5.I’m terrified of the snakes. 我害怕蛇。
內(nèi)容提示本單元主要內(nèi)容是學(xué)會利用verb十by/with gerund表示方式方法來討論學(xué)習(xí)英語的策略,認(rèn)識自己在學(xué)習(xí)方面的長處和不足。初步了解現(xiàn)在完成時的結(jié)構(gòu)和用法?,F(xiàn)在完成時由助動詞have/has+動詞的過去分詞構(gòu)成,主要表示過去發(fā)生的某一動作對現(xiàn)在仍有影響或造成的后果,常與already,yet,just,ever,never等副詞連用。教學(xué)目標(biāo)一、學(xué)習(xí)目標(biāo)(Language Goal) 1. Talk about how to study . 學(xué)會討論各種學(xué)習(xí)方法和策略。2. Find out your suitable learning methods. 找出適合自己的學(xué)習(xí)方法。 二、語言結(jié)構(gòu)(Language Structures) 1. Verb + by with gerund by+動名詞短語 表示“通過…途徑,方法” 2. How questions have引導(dǎo)的特殊疑問句 三、目標(biāo)語言(Target Language) 1. How do you study for tests ? 你是怎樣準(zhǔn)備考試的?Well , I study by working with my classmates. 哦,我和同學(xué)們一起學(xué)習(xí)。2. Have you ever studied with a group ? 你曾經(jīng)參加過學(xué)習(xí)小組嗎?Yes , I have . I’ve learned a lot that way . 是的,參加過。通過這種方式我學(xué)了許多。
一、Section A該部分有4個模塊。第一模塊圍繞Whose volleyball is this? 這一話題展開思維( 1a)、聽力(1b)、口語( 1c)訓(xùn)練;第二模塊圍繞上一模塊中的話題進(jìn)行聽力( 2a-2b)、口語訓(xùn)練( 2c);第三模塊繼續(xù)圍繞前兩個模塊中的“making inferences”展開訓(xùn)練。訓(xùn)練形式為閱讀排序( 3a)和兩人問答(3b);第四模塊仍就上一話題展開討論。二、Section B該部分有4個模塊。第一模塊要求根據(jù)圖畫和所提供的單詞寫出合理的句子;第二模塊在聽力( 2a-2b)和分角色口語訓(xùn)練( 2c)的基礎(chǔ)上,繼續(xù)進(jìn)行“推測”訓(xùn)練; 第三模塊圍繞“Strange events in Bell Tower neighborhood”這一話題展開閱讀( 3a)和寫作(3b -3c)訓(xùn)練;第四模塊以dream為話題展開小組活動。三、Self Check該部分有3個模塊。第一模塊以填空形式對所學(xué)詞匯進(jìn)行訓(xùn)練;第二模塊就8個諺語展開閱讀和討論。
The First PeriodⅠ.Teaching Aims and DemandsKnowledge Objects(1) Key Vocabularytiring, educational, fascinating, thrilling, peaceful, exotic, trek, jungle, take it easy, explore, historic, site(2) Target LanguageWhere would you like to go on vacation?I’d like to trek through the jungle, because I like exciting vacations.2. Ability Objects(1)Train students to talk about places they would like to visit with the target language.(2)Train students to describe vacations with different adjectives.(3)Train students' listening skill.3. Moral Object,It′s more interesting to go on vacating somewhere instead of staying at home.Ⅱ. Teaching Key Points1. Key Vocabularytiring, educational, fascinating, thrilling, peaceful, exotic, trek, jungle, take it easy, explore, historic, site2. Target LanguageTalk about different places with the target language.Ⅲ. Teaching Difficult Points1. Describe vacations with different adjectives.2. Talk about different places with the target language.Ⅳ. Teaching Methods1. Teaching by illumination2. Teaching by doing chain drills3. Teaching by pairworkⅤ. Teaching Aids1. A tape recorder2. Some pictures of different places with famous views
1、結(jié)合具體生活場景,能運用所學(xué)的乘法口訣解決簡單的實際問題,通過圖與式的對應(yīng),進(jìn)一步理解乘法的意義。 2、能熟練運用口訣進(jìn)行計算,提高靈活運用口訣解決實際問題的能力。 3、體會數(shù)學(xué)與實際生活的聯(lián)系,培養(yǎng)用數(shù)學(xué)的意識,體驗口訣在解決問題中的作用。 運用所學(xué)乘法解決簡單的實際問題。 結(jié)合實際情景理解乘法的意義。 1、口算: 5×2=10 6×2=12 8×5=40 2×7=14 5×9=45 3×5=15 2×6=12 2×9=18 4×2=8 2、談話導(dǎo)入:在前面的學(xué)習(xí)中,我們認(rèn)識了乘法,而且還學(xué)習(xí)了2和5的乘法口訣。這節(jié)課,老師想請同學(xué)們用這些跟乘法有關(guān)的知識來幫助老師一起解決生活中遇到的問題,一起來看一看吧??鞓沸菹r間到了,學(xué)校的大操場突然熱鬧起來了,你們一定非常喜歡課件活動吧!看,操場上同學(xué)們有的在玩老鷹捉小雞的游戲,有的在進(jìn)行乒乓球比賽,有的在跳繩,還有的在踢毽子……真熱鬧??!
[師]同學(xué)們想一想,你同父母一起去商店買衣服時,衣服上的號碼都有哪些,標(biāo)志是什么?[生]我看到有些衣服上標(biāo)有M、S、L、XL、XXL等號碼.但我不清楚代表的具體范圍.適合什么人穿.但肯定與身高、胖瘦有關(guān).[師]這位同學(xué)很善動腦,也愛觀察. S代表最小號,身高在150~155 cm的人適合穿S號.M號適合身高在155~160 cm的人群著裝…….廠家做衣服訂尺寸也并不是按所有人的尺寸定做,而是按某個范圍分組批量生產(chǎn).如何確定組距與組數(shù)呢?分組組數(shù)的確定,不僅與數(shù)據(jù)多少有關(guān),還與數(shù)據(jù)的取值情況有關(guān).在實際決定組數(shù)時,常有一個嘗試過程:先定組距,再計算出相應(yīng)的組數(shù).看看這個組數(shù)是否大致符合確定組數(shù)的經(jīng)驗法則.在嘗試中,往往要比較相應(yīng)于幾個組距的組數(shù),然后從中選定一個較為合適的組數(shù).我們一起看下表:小亮的做法.