一、教材分析《請幫我一下吧》是統(tǒng)編教材小學(xué)《道德與法治》一年級下冊第四單元第14課,共有四個話題,本節(jié)課學(xué)習(xí)的是后兩個話題《我會求助》和《溫暖的“接力棒”》,主要是引導(dǎo)學(xué)生學(xué)習(xí)如何向人求助,領(lǐng)悟幫助他人的價值與意義,旨在引導(dǎo)學(xué)生懂得生活中受助于人和幫助別人,體會在和諧互助的社會生活的溫暖。二、學(xué)情分析學(xué)會求助的基本技能,懂得不僅要能,懂得感恩,也要學(xué)會幫助他人,讓友愛與互助精神得到傳遞養(yǎng)成互相幫助的好習(xí)慣,為學(xué)生的健康成長奠定基礎(chǔ)。一年級的學(xué)生年紀(jì)小,獨(dú)立性相對較差,他們在家中備受寵愛,很多家長對孩子的生活、學(xué)習(xí)等事務(wù)都一手包辦,以至于遇到困難時有的過度依賴,有的不愿意向別人求助,有的不敢向別人求助。因此,要通過有效的教學(xué),幫助引導(dǎo)學(xué)生學(xué)會求助,懂得互幫互助。三、教學(xué)目標(biāo)與重難點(diǎn)基于教材、學(xué)情的分析,以及對小學(xué)道德與法治課程的理解,我確定了本節(jié)課的教學(xué)目標(biāo)與重難點(diǎn)。教學(xué)目標(biāo)我確定了三個。1.學(xué)會求助的基本技能。2.懂得互相幫助的價值和意義。3. 養(yǎng)成互相幫助的好習(xí)慣。
一、說教材本課是二年級《道德與法治》第四單元最后一課,通過兩年的學(xué)習(xí),每個學(xué)生都獲得不同程度的進(jìn)步和成長,所以這一課依據(jù)課程標(biāo)準(zhǔn)“愉快、積極地生活”,旨在引導(dǎo)學(xué)生對此進(jìn)行梳理總結(jié),發(fā)現(xiàn)自己的優(yōu)點(diǎn)和長處,并為自己在學(xué)習(xí)中取得的進(jìn)步感到高興和自豪,確立成長的自信,以此激勵自己不斷進(jìn)步。同時,引導(dǎo)學(xué)生過有計劃的生活,明確自己下一步發(fā)展任務(wù),以積極地心態(tài)、有準(zhǔn)備地面對中年級的過渡。 說學(xué)情: 本課主要引導(dǎo)學(xué)生對自己兩年來的成長與進(jìn)步進(jìn)行梳理與總結(jié),總結(jié)具有抽象性和概括性,對低年級的學(xué)生來說,具有一定的難度。兩年的時間,跨度長,如何有效引導(dǎo)進(jìn)行比較;如何準(zhǔn)確發(fā)現(xiàn)目前存在的問題,不是簡單地文本遷移并將抽象的發(fā)展目標(biāo)落實為具體的能力發(fā)展,都是在教學(xué)中需要解決的問題。二、說教學(xué)目標(biāo): 1、學(xué)會根據(jù)自己所做的正確事,來獎勵自己; 2、不只是獎勵自己,還要學(xué)會獎勵周圍的同學(xué),伙伴; 3、我們都有需要努力的地方,學(xué)會設(shè)個未來獎,爭取以后做的更好。 教學(xué)重難點(diǎn):學(xué)會根據(jù)自己所做的正確事,來獎勵自己,還要學(xué)會獎勵周圍的同學(xué),伙伴
8. 2022 年,俄烏沖突以來,美方不斷泛化國家安全概念,濫用出口管制措施, 多次以所謂“人權(quán)”等為由,對中國企業(yè)無理打壓,嚴(yán)重破壞國際經(jīng)貿(mào)規(guī)則。 同時美國不顧中方多次警告,將航母駛?cè)肽虾_M(jìn)行挑釁,美國國會操弄“臺灣地圖牌” 。面對美方的無端打壓和干涉,我國應(yīng)該 ( )A.謙讓機(jī)遇,合作共贏,與美國共發(fā)展B.抓住機(jī)遇,迎接挑戰(zhàn),積極謀求發(fā)展C.集中力量,增強(qiáng)實力,掌控世界趨勢D.主動迎擊,不畏強(qiáng)權(quán),鞏固霸主地位9. 中華詩詞濃縮了中華文化的精華,經(jīng)過歲月的沉淀仍然閃爍著時代的光芒。 從下列經(jīng)典詩句中得到的啟示,你認(rèn)為不正確的是 ( )A.“萬物并育而不相害,道并行而不相?!薄趪H交往中我國要堅持合作、共贏的理念,做到互信互利 B.“國雖大,好戰(zhàn)必亡;天下雖平,忘戰(zhàn)必亡”— 中國要屹立于世界民族之林,必須通過戰(zhàn)爭樹立國際地位C.“天與不取,反受其咎;時至不行,反受其殃”—機(jī)遇稍縱即逝,我們要抓住機(jī)遇,勇于創(chuàng)新,追求發(fā)展D.“同心掬得滿庭芳”—各族人民要鑄牢中華民族共同體意識,手足相親、守望相助10.從漫畫“新四大發(fā)明”中,下列認(rèn)識和理解正確的有 ( )①我們要培育壯大經(jīng)濟(jì)發(fā)展新動能②我國把提升發(fā)展質(zhì)量放在首位③中國決定著世界經(jīng)濟(jì)發(fā)展的趨勢④中國與世界各國共享發(fā)展成果
Teaching Goal:1. General aims:Talk about recent past events2. Particular aims:A. Language Focus.Talk about recent past events and think of the past events.B. Language goalsHow was….?It was …What did …do over the weekend?C. Language structures:(1). How was your weekend? I was great. Pay attention to no form.(2). What did you do over the weekend? I played soccer. We went to the beach.D. Useful words and phrases:Words: was, did, went, beach, over, project, test, wasn’t, false, number, geography, spend, week, most, mixture, their, had, little, cook, read, saw, change, everyone, sit, sat, no, anythingPhrases: did one’s homework, played soccer, cleaned my room, went to the beach, played tennis, went to the movies, on Saturday morning, over the weekend, cook … for, what about, do some reading, have a party, talk show, go shoppingE. Grammar language:Present simple past tenseRegular and irregular verbsF. Learning strategies:Tour and holidaysG. Interdiscipinary:H. Emotion and manner:Teaching time: 5 periodsTeaching procedures:Period One教學(xué)步驟、時間 教師活動 學(xué)生活動 媒體應(yīng)用Step 1Free talk 3’ Ask some questions like:Who’s on duty today?What’s the weather like? Answer and talk about something.讓同學(xué)們回答下列問題1. Do you like weekend? (Let some students answer)It takes them three minutes to talk about the question.2. Why do you like weekend? (let the students answer) Most of the students like the weekend此時教師用漢語問:“在周末期間問你干了什么?這句話用英語這么回答?Let the students guess.At last the teacher give them right answer3. What did you do over the weekend?(板書、學(xué)習(xí))
Period 2 (3a----Section B 2c)Preview(Pre-task): Key points: What laAdd another information about their pen pals----their language on the cardnguage does she/he speak?She/He speaks....Does she/he have any brothers and sisters? Does she/he speak English?Preview(Pre-task): Add another information about their pen pals----their language on the cardKey points: What language does she/he speak?She/He speaks....Does she/he have any brothers and sisters? Does she/he speak English?Step 1 Revision1.Revisionand dictation of the new words 2.Revise the drills they learned yesterday.(by pairwork and grammar exercise)Step 2 Leading-inT has a conversation with one student. The conversation is following:---Do you have a pen pal?---Yes, I do.---What's your pen pal's name? ---His/Her name is....---Where is your pen pal from? ---He/She is from...---Where does he/she live? ---He/She lives in....---What language does he/she speak?He/She speaks...Write the new words on the Bb. They are following: EnglishChineseJapaneseFrenchStep 3 LearnLearn the new words with the whole class.Finish 3a with the students3b Pairwork T still does an example with one student Then the Ss practise in pairs. The example is following:--Curry Muray is my pen pal. He is from the United States.---What language does he speak?
Don’t fight. =You can’t fight. (板書,教讀)教師把這些句子板書在黑板上,并請學(xué)生大聲整齊地讀祈使句和“can’t”句型,并讓學(xué)生注意兩種句型表達(dá)形式的不同和轉(zhuǎn)換,“Don’t …=You can’t…”;并對學(xué)生說:These are our school rules. (板書,教讀) You can’t break the school rules. Don’t break the school rules.(板書,教讀)步驟3 :Practicea. T: Now, each of the students is breaking one of these rules.Please finish 1a.學(xué)生看圖,完成1a的內(nèi)容,檢查答案并大聲朗讀校規(guī)。b. 聽錄音,完成1b,選出四位學(xué)生都違反了哪條校規(guī);聽之前,學(xué)生要讀會英文名。c. 請兩位學(xué)生朗讀1c部分的句型;要求學(xué)生兩人一組對話表演,SA扮演外校轉(zhuǎn)來新生,SB告知本校校規(guī)。(學(xué)生可經(jīng)過討論,多說出他們想到的校規(guī),不必只限于書上;教師應(yīng)給予幫助)2) 第二課時(2a~4)步驟1 :warming up of revisionT: What are the rules at your school?學(xué)生使用“can”或祈使句表達(dá)各條校規(guī);其中老師可引出“eat in the cafeteria outside”的表達(dá)。步驟2 :Practicea.T: Christina is an exchange student. She doesn’t know the rules. Let’s listen, what activities they’re talking about?學(xué)生聽第一遍時,完成2a;第二遍時,完成2b;b. 請學(xué)生領(lǐng)讀2c部分,看著2a完成的表格,理解2c活動的要求;分成小組針對2a進(jìn)行問答;
區(qū)分賓語從句、定于從句和狀語從句賓語從句和狀語從句,都叫做主從復(fù)合句。賓語從句主要是中考必考的,是初中階段必掌握的從句,賓語從句主要是掌握三要素,所謂賓語從句,就是賓語在主從復(fù)合句當(dāng)中充當(dāng)賓語的一個句子,叫做賓語從句。主句的謂語動詞是及物動詞,后面如果是詞或者是短語的話,是簡單句,如果是句子的話,肯定是賓語從句。I know that he good at English.就是賓語從句,三要素,一要素是要注意連詞,連詞一共學(xué)了三類連詞,一類連詞是that口語當(dāng)中可以省略,就像剛才說的那一句,I hear he is good at English.還有疑問代詞、疑問副詞,how where when,疑問代詞、疑問副詞。還有一類連詞weather是否的意思,不是狀語從句當(dāng)中的如果,這一定要和如果區(qū)分開,這是是否。I don't know if he interested at English。賓語從句要注意if是連詞。第二要素是語序,要用陳述舉語序。比如說你家有幾口人,我們都說How many people are there in you family?但是這是簡單句,一旦說成賓語從句,你可以告訴我你家有幾口人嗎?Could you tell me how many people there are in you family ?
Step Ⅱ Show the new words on the screen and teach the new words. Read the new words to students and ask them to repeat.Step Ⅲ 3aThis activity introduces new vocabulary and provides reading practice using the target language.In this activity first look at the four pictures.T: What can you see in the pictures?Ss: Four snow globes.T: Right. There are four snow globes in the pictures. And what are they?Ss: They are a monster, two polar bears, two penguins and a birthday cake.Write these words on the blackboard: snow globe; monster; polar bear; penguin and birthday cake. Read them to the class and ask students to repeat each one. Make sure students understand each word.Use a computer to show the E-mail message on the screen and read the message to students.Get students to read the e-mail on their own, and then draw lines connecting each snow globe and its description.Correct the answers.AnswersA line should connect each snow globe picture with the words that describe it in the letter.Step Ⅳ 3bThis activity provides writing practice using the target language.First review Activity 2a on Page 47.Then ask students to complete the message according to Activity 2a.Some partial sentences are given to students. Write about one person's collection.When students work, walk around the room checking the progress and offering help as needed.When they finish, ask some students to read their messages to the class.
所需要用到的句子:Who is that?That is Jack. I like him.Why do you like him?I like him because he is interesting.Task 4: 設(shè)計理想中的人類Step one: 設(shè)計理想中的人類的外貌。把全班同學(xué)分成若干小組,學(xué)生可以邊說邊在紙上畫出他們的模樣。Step two: 設(shè)計理想中人類的性格。學(xué)生們可以把那些能描述性格的單詞寫在圖畫的旁邊。Step three: 每組選出一名同學(xué),其他同組同學(xué)提問,他作簡單回答,并說明原因。所需用到的句子:What does he or she look like?He or she ...What is he or she like?He or she is ...Why?Because ...Task 5: 挑戰(zhàn)性活動調(diào)查性格是天生的還是后天形成的,讓每個同學(xué)回家去調(diào)查一下自己成長過程中性格是否有變化,具體是怎樣的,為什么會這樣? Teaching Aims:1. Enable students to have a general understanding of how to talk about people's physical appearance.2. Enable students to tackle some essential vocabularies and patterns about describing people. Provide them with necessary skills and methods.3. Create various chances for students to describe the persons they're familiar with, such as classmates, family members, teachers, idols, etc.
三、教學(xué)建議第一課時:1. Lead in (Vocabulary)A) Before class, teacher should collect some pictures of working places. For example: Bank, TV Station, Restaurant, Police Station, Hospital ...B) In class, show students the pictures (PowerPoint, OHP). Ask students to tell the name of the working places and the name of the jobs.Shop assistant, doctor, actor, reporter, police office, waiter, bank clerk, studentC) Do exercise 1a and 3a.2. Bingo GameAsk groups of students to make up pairs of cards with a job on one and the related workplace on the other. For example, waiter / restaurant, teacher / school, doctor / hospital. Encourage students to use both the job / workplace combinations in the book and the ones that students came up during class discussions. Be sure they have twice as many sets of cards as there are students in the group. They can make two sets of cards for a single job / workplace, if necessary. Then have each group mix up its set of cards and hand their cards out in random order. Each time a student gets a pair of cards that match, he or she can lay these cards down. The goal is to have no cards in your hand at the end.3. Task OneA) Ask students to work in pairs and ask the partner what does he / she want to be in the future.e. g. :What do you / does he / does she want to be?I want to be a.Why?Because it's (adj).B) Vocabulary: Section B, 1a4. Homework 1.2.
1 Each group choose one place to describe and what you are doing in it Choose one place, and describe what they are doing 2 Move around the room and give suggestions Talk about it and write it down 3 Ask one to show their works and act it Choose one of each group to make a report 4 Evaluate the best group and the best reporter Choose the best one Homework Ask your friends their ideal place and write about it教學(xué)反思:新課程標(biāo)準(zhǔn)中強(qiáng)調(diào)學(xué)生在課堂中的主體地位,在綜合課中他們的主體地位就更加突出。在各個活動中給不同程度的學(xué)生不同層次的任務(wù),讓各層面的學(xué)生都有表現(xiàn)發(fā)揮的機(jī)會,從而產(chǎn)生對英語的興趣。使用照片圖片多媒體來輔助教學(xué),效果更好。同時讓了解其他國家風(fēng)景,風(fēng)俗的同學(xué)介紹ideal place,增加學(xué)生的背景知知識,實現(xiàn)跨學(xué)科交流的目的。教案點(diǎn)評:采用任務(wù)型教學(xué)模式,在各個活動中給不同程度的學(xué)生不同層次的任務(wù),讓各層面的學(xué)生都有表現(xiàn)發(fā)揮的機(jī)會,從而產(chǎn)生對英語的興趣。使用照片圖片多媒體來輔助教學(xué),效果更好。讓了解其他國家風(fēng)景,風(fēng)俗的同學(xué)介紹ideal place,增加學(xué)生的背景知識,實現(xiàn)跨學(xué)科交流的目的。
單元整體說明(一)單元教材分析本單元的核心話題是描述動物和表達(dá)個人喜好,以及句式why do you like…? Because…。這也是本單元的教學(xué)重點(diǎn)。通過本單元的學(xué)習(xí),學(xué)生應(yīng)能較流利地運(yùn)用所學(xué)詞匯和句型描述動物,表達(dá)個人喜好。(二)單元知識結(jié)構(gòu)1.詞匯動物名稱 tiger, elephant, koala, dolphin, etc.詞匯描述性形容詞: smart, cute, ugly, clever, shy, etc.國家名: Australia, South Africa2.句型Why do you like koala hears? Because they are cute.Where are pandas from? They're from China.What animals do you like? I like dolphins.(三)單元整體目標(biāo)1.Master the vocabulary2.Master and use: Why do you like koalas? Because they am cute.Where are pandas from? They're from China.What animals do you like? I like dolphins.(四)單元教學(xué)重難點(diǎn)一覽(五)單元學(xué)情分析學(xué)生此前已經(jīng)學(xué)過由why, where, what 引導(dǎo)的特殊疑問句句型,具有了學(xué)習(xí)本單元知識的認(rèn)知前提。形形色色的動物能激發(fā)學(xué)生的好奇心,產(chǎn)生了解它們的欲望,這有利于本單元知識的教學(xué)和學(xué)生學(xué)習(xí)興趣的培養(yǎng)。
說明:在幫Li Lei提建議的同時,教育學(xué)生如何學(xué)好英語。第三課時教學(xué)目標(biāo)1. 語言目標(biāo):a) 詞匯: Original, in style, haircut, the same as.b) 語言結(jié)構(gòu):My friend wears the same clothes and has the same haircut as I do.2. 能力目標(biāo):大多數(shù)學(xué)生能夠談?wù)撟约合矚g哪種服裝,提高查找信息的能力。3. 情感目標(biāo):學(xué)會如何與朋友相處,要有自己對時尚的看法。教學(xué)重點(diǎn)掌握一些重要詞匯。教學(xué)難點(diǎn)學(xué)會談?wù)搯栴},并能提出書面建議?!艚虒W(xué)突破首先針對Erin的問題,提出個人的建議,模仿2c部分的對話展開雙人交際Pair-work;聽老師誦讀3a部分的信件,并找出LEFT OUT的問題所在;學(xué)生完成3b部分的內(nèi)容,給Left Out提出書面的建議;學(xué)以口頭形式提出自己目前存在的某個問題,講給大家聽,讓同學(xué)們給自己提出一個建議,并作筆錄;學(xué)生兩、三個人分成一組,隨意性地進(jìn)行口語交際,談?wù)揚(yáng)14的第4部分的某個問題,相互交換意見。
"Hello! Welcome to English class! Introduce yourself. Meet your new classmates." That's what the teacher says. What do you say? "Oh no!" It can be difficult talking to new people. But it can be fun, and you can make friends. How do you do it? Make small talk. Small talk is polite conversation. "Wang Nan is a great pingpang player, isn't she?" "I'd love to meet her, wouldn't you?" "It's been raining a lot, hasn't it?" Tag questions are a form of polite speech. To make small talk successfully, you should know how to make them. You should also know what topics to talk about. Try to learn this unit carefully. The next time you're in English class, you'll find out. Making small talk's easy, isn't it? (“你好!歡迎你!請做一下自我介紹。認(rèn)識一下你的新同學(xué)。”通常在課上老師會這樣說。你會說什么呢?“噢,不!”與陌生人談話太困難了。但是這也很有意思,并且你還能交到朋友。你該怎么做呢?閑聊。閑聊指得是禮貌的對話?!巴蹰且粋€很棒的乒乓球運(yùn)動員,不是嗎?”“我希望自己能認(rèn)識她,你呢?“今年的雨水很多,不是嗎?”反意疑問句是一種禮貌用語。為了使得談話成功,你應(yīng)該知道怎樣去進(jìn)行閑聊。你還應(yīng)該知道與不同的人該談?wù)撌裁礃拥脑掝}。認(rèn)真的學(xué)習(xí)這個單元吧,下次在英語課上,你會發(fā)現(xiàn)與大家展開談話是一件很容易的事情,不信我們來試試。)
This activity introduces some new vocabulary and provide oral practice using the target language.Task 1 . Ask four students to stand in front of the class, and the teacher asks them the following questions as a reporter.1.What are you going to do when you grow up?2.What are you going to do next week?3.What are going to do after school?The students will give different answers, then ask a good student to report what they said.I am going to e a doctor.What did she say?----------She said she was going to be a doctor.I am going to have a party on Friday night.What did he say?-------He said he was going to have a party on Friday night.I am going to do my homework.What did she say ?------ She said she was going to do her homework.I am going home after school.What did she say?-----She said she was going home after school.Say In this unit we are going to learn to use words like to report what someone said.Task 2. Read the instructions. Then ask a student to read the four questions. And write the words on the Bb. Explain what soap opera is.Task 3. Ask the students to Look at the pictures, point out the TV screens in the picture. Ask one girl to read what Marcia said.What did Marcia say? She said She said she was having a surprise party for Lana on Friday night. Repeat the other pictures in the same way.Activity3. Listen and number the pictures in activity 1a.
(一).知識方面: 1.培養(yǎng)學(xué)生能運(yùn)用過去進(jìn)行時來描述、談?wù)撨^去某個時間正在發(fā)生的事情或動作的意識和能力,能就過去某個時間正在發(fā)生的動作做出正確的描述。 2.培養(yǎng)學(xué)生的想象力和角色扮演的合作能力。 3.培養(yǎng)學(xué)生講述過去發(fā)生的事情經(jīng)過的能力。能正確運(yùn)用一般過去時來講述故事。 (二).技能方面: 1.本單元的語言目標(biāo)是Talk about past events and tell a story(談?wù)撨^去的時間和講述一個故事),圍繞這一目標(biāo),要涉及句型: What were you doing when the UFO arrived? ----I was sitting in the barber’s chair. The barber was cutting my hair. 因此必須學(xué)習(xí)standing、studying、cleaning、sleeping、cooking、making、eating、cutting、等表示地點(diǎn)的詞,以便為上述句型提供語言材料。2.學(xué)習(xí)過去進(jìn)行時的有關(guān)知識。Was/were+現(xiàn)在分詞,是該時態(tài)的表達(dá)式。 3.在學(xué)習(xí)過程中,要區(qū)分The boy was walking down the street when the UFO landed.和While the boy was walking down the street, the UFO landed.這兩種由when和while引導(dǎo)的狀語從句的句型結(jié)構(gòu)。注意它們的不同。
本單元主要圍繞著有關(guān)瀕臨滅絕的動物這一話題,學(xué)習(xí)了應(yīng)該怎樣保護(hù)我們的環(huán)境,以及就某一問題展開辯論。目標(biāo)提示語言目標(biāo)能夠運(yùn)用所學(xué)知識,就某一問題展開辯論。認(rèn)知目標(biāo)1、復(fù)習(xí)一些語法:現(xiàn)在進(jìn)行時、一般現(xiàn)在時、用used to 表示一般過去時、現(xiàn)在完成時、一般過去時的被動語態(tài)。2、學(xué)會表達(dá)同意和不同意。3、學(xué)會以下基本句型:We’re trying to save the manatees.Manatees eat about 100 pounds of food a day.There used to be a lot of manatees.In 1972,it was discovered that they were endangered.Some of the swamps have become polluted.情感目標(biāo)了解一些瀕臨滅絕的動物的生活習(xí)性和瀕臨滅絕的原因,教育學(xué)生應(yīng)該如何保護(hù)環(huán)境。教學(xué)提示充分利用多媒體等教學(xué)設(shè)備,創(chuàng)設(shè)與本課話題相關(guān)的情境,如各種不同種類的動物、動物園以及有關(guān)環(huán)境的畫畫等等。圍繞著本單元的教學(xué)目標(biāo),設(shè)計一些貼近學(xué)生實際的教學(xué)任務(wù),如讓學(xué)生談?wù)撟约鹤钕矚g的動物,如何拯救瀕危動物,如何保護(hù)環(huán)境等等。讓學(xué)生根據(jù)所學(xué)知識,就動物園是否對動物有利以及其他的話題進(jìn)行辯論。
教學(xué)要求1. 通過生活中的事例,學(xué)會解決“找次品”這類問題的思想方法。2. 體會解決問題策略的多樣性及運(yùn)用優(yōu)化的方法解決問題的有效性。3. 感受到數(shù)學(xué)在日常生活中的廣泛應(yīng)用,培養(yǎng)應(yīng)用意識和解決實際問題的能力。學(xué)情分析有化是一種重要的數(shù)學(xué)思想方法,可有效地分析和解決問題。本單元主要以“找次品”這一操作活動為載體,讓學(xué)生通過觀察、猜測、推理的方法感受解決問題策略的多樣性,在此基礎(chǔ)上,通過歸納、推理的方法體會運(yùn)用優(yōu)化策略解決問題的有效性,感受數(shù)學(xué)的魅力。這些內(nèi)容對五年級的學(xué)生來說有一定的難度,所以應(yīng)讓學(xué)生在具體操作和試驗中感悟、體會,由此使學(xué)生養(yǎng)成勤于思考、勇于探索的精神。教學(xué)重點(diǎn)學(xué)會解決“找次品”這類問題的方法。
《貼郵票》活動要求:A、每組4人,給四封不同地點(diǎn)、質(zhì)量的信件B、根據(jù)信封上的信息計算郵費(fèi)并按要求貼上郵票(郵票的總面值剛好等于郵費(fèi),不能多貼)每封信最多貼三張郵票,只有0.8元或1.2元的兩種郵票紀(jì)律要求:看看哪組合作得最好,速度最快!如果遇到困難,在事發(fā)那個在一邊最后再去解決。3、小組匯報(1)、貼郵票的過程中大家遇到了什么問題?(有的能貼有的不能貼)這樣的信件有哪些?(告訴我地點(diǎn)、質(zhì)量、郵費(fèi))(2)、其他的信件都能貼出來嘛?說說看你是怎么貼郵票的?(3)、請將你們貼好郵票的信件送到郵箱來。剩下的都是一些“難題”(4)、思考:為什么4.0元、4.8元、6元的郵費(fèi)沒有辦法按要求貼出郵票?(5)、原因出在哪里?這個問題怎么解決?(郵票面值太小,將郵票的面值改大)(6)、那最少要改成多大的?為什么?(將郵票面值改大,你會從多大面值的郵票開始考慮?為什么?)
師:同學(xué)們,在四年級的時候,我們已經(jīng)了解了圖形的密鋪,請你說一說,什么是圖形的密鋪?(沒有重疊、沒有空隙地鋪在平面上,就是密鋪。)師:圖形的密鋪又可以叫做鑲嵌,以上四個圖片,都是由哪些基本圖形密鋪(鑲嵌)而成的呢?(請學(xué)生邊指邊說。)師:還有哪些圖形也可以鑲嵌?(學(xué)生可能回答:三角形,平行四邊形,梯形,菱形,正六邊形,……)師:今天就請你發(fā)揮一下想象力,設(shè)計一些與眾不同的鑲嵌圖形。[設(shè)計意圖說明:學(xué)生在四年級已經(jīng)初步了解了圖形的密鋪(鑲嵌)現(xiàn)象,四幅圖片是四年級下冊教材《三角形》單元中《密鋪》內(nèi)容中的原圖。本單元在此基礎(chǔ)上,通過數(shù)學(xué)游戲拓展鑲嵌圖形的范圍,讓學(xué)生用圖形變換設(shè)計鑲嵌圖案,進(jìn)一步感受圖形變換帶來的美感以及在生活中的應(yīng)用。]二、新授探究一:利用平移變換設(shè)計鑲嵌圖形