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新人教版高中英語必修3Unit 5 the value of money-Reading For Writing教學設(shè)計一
【參考范文】Narrator：(Henry is smiling as he leaves the restaurant. As he is walking down the street, he sees a sign for a place that cuts hair. He decides to get it cut. )H＝Henry；B＝Barber；R＝rude manH：Good afternoon, I'd like to get a cut, if I may. (The barber looks at Henry's hair and continues cutting another man's hair. )Er, I'd really like a haircut. As you can see it's much too long. B：(in a rude manner) Yes, I can see that. Indeed, I can. H：Fine, well I'll have a seat then. (He sits in one of the barber's chairs. The barber turns to look at Henry. )B：It's quite expensive here, you know！Are you sure you can afford it?H：Yes. I think so. (In comes the rude man. )R：Hey you there. I need a haircut quickly. Can you do me straightaway?B：All right, then, get in the chair and I'll see what I can do. R：Thank you. (sits down in one of the barber's chairs)H：Excuse me, but I was here first. Aren't you going to do my hair first?B：This man's in a hurry. H：Well so am I！I insist that you cut my hair first. B：OK, but I'll have to be quick. This gentleman is waiting. H：Thank you. (They both become quiet. After his hair is cut, the barber tells Henry how much he must pay. Henry shows the barber the bank note. )B：Why, Mr . . . (looks shocked)H：Adams. Henry Adams. I'm sorry, I don't have any change. R：You're that Mr Adams! Well，I'm glad I waited or I might never have known it was you. B：Why, Mr Adams, please don't worry！(wearing a big smile) Nothing to worry about！Nothing at all!Please come back any time, even if you only need too little hairs cut！It will be my honour to serve you!
新人教版高中英語必修3Unit 1 Festivals and celebrations-Discovering Useful Structure教學設(shè)計
4.That was an experience that frightened everyone. →That was _____________________. 答案：1. taking 2. being discussed 3. in the reading room 4. a frightening experienceStep 6 The meaning and function of V-ing as the predicative動詞-ing形式作表語，它通常位于系動詞后面，用以說明主語“是什么”或“怎么樣”一種表示主語的特質(zhì)、特征和狀態(tài), 其作用相當于形容詞; 另一種具體說明主語的內(nèi)容, 即主語等同于表語, 兩者可互換。The music they are playing sounds so exciting. 他們演奏的音樂聽起來令人激動。The result is disappointing. 結(jié)果令人失望。Our job is playing all kinds of music. 我們的工作就是演奏各種音樂。Seeing is believing. 眼見為實。Step 7 Practice1. It is ________(amaze) that the boy is able to solve the problem so quickly.2. Buying a car is simply _______(waste) money. 3. Please stop making the noise—it’s getting ________(annoy). 4. complete the passage with the appropriate -ing form.La Tomatina is a festival that takes place in the Spanish town Bunol every August. I think many food festivals are __________ because people are just eating. however, this festival is _________ because people don't actually eat the tomatoes. Instead, they throw them at each other! the number of people ________ part in this tomato fight, can reach up to 20,000, and it is a very __________ fight that lasts for a whole hour. The _______ thing is how clean Bunol is after the tomatoes are washed away after the fight. this is because the juice form tomatoes is really good for making surfaces clean!答案：1. amazing 2. wasting 3. annoying4. boring interesting taking exciting amazing
新人教版高中英語必修3Unit 1 Festivals and Celebrations-Listening &Speaking＆Talking教學設(shè)計
The theme of this section is “Talk about festival activities and festival experiences”.Festival and holiday is a relaxing and interesting topic for students. This part talks about the topic from the daily life of students’. In the part A ---Listening and Speaking, there are three conversations among different speakers from three countries(Japan, Rio and China), where the speakers are participating in or going to participate in the festivals and celebrations. So listening for the relationship among them is a fundamental task. Actually, with the globalization and more international communication, it is normal for Chinese or foreigners to witness different festivals and celebrations in or out of China. In the Conversation 1, a foreign reporter is interviewing a Japanese young girl who just had participated in the ceremony of the Coming-of-Age Day on the street and asking her feeling about the ceremony and the afterwards activities. Conversation 2, Chinese girl Li Mei is witnessing the Rio Carnival for the first time, and her friend Carla gives her some advice on the costumes which enables her to match with the carnival to have a good time. Conversation 3, a Chinese guide is showing a group of foreign visitors around the Lantern Festival and introducing the customs of the festival to them. The three conversations have a strong vitality and insert the festival and cultural elements from different countries. So perceiving the festivals and cultures from different countries is the second task. At the same time, the scripts also insert the targeted grammar --- v-ing as attributive and predicative, which students can perceive and experience in a real context and make a road for the further study. That is the third task. In the Part B--- Listening and Talking, the theme is “Talk about festival experience”, which is the common topic in our daily conversations. During the conversation, Song Lin, a Chinese student, asked Canadian friend Max about how to spend Christmas. In the conversation, Song Lin talked about experience and the feelings during the Chinese Spring Festival, during which there are not only some enjoyable things but some unpleasant things. After the listening, perhaps students find there are some similarities between Christmas and the Chinese Spring Festival as there are some differences in the origins and celebrations. For example, people always visit friends and relatives, decorate their houses, have a big dinner together, chat and give presents to each other.
新人教版高中英語必修3Unit 2 Morals and Virtues-Discovering Useful Structure教學設(shè)計
1. 表示時間。Hearing these stories, I’m skeptical about the place. = When I heard these stories. . . 2. 表示原因。Not knowing his address, I can’t send this book to him. = Because/Since/As I don’t know his address. . . 3. 表示結(jié)果。His father died, leaving him a lot of money. =. . . and left him a lot of money4. 表示條件。Going straight down the road, you will find the department store. = If you go straight down the road. . . 5. 表示讓步。Being tired, they went on working. =Although they were tired. . . 6. 表示行為方式、伴隨情況或補充說明。He lay on the grass, staring at the sky for a long time. =. . . and stared at the sky for a long time注意：非謂語動詞作狀語時, 如所提供的動詞不能和句子中的主語保持一致, 動詞-ing形式必須有自己的邏輯主語, 通常由名詞或代詞來擔任, 這就是獨立主格結(jié)構(gòu)。The last bus having gone, we had to walk home. (having gone的邏輯主語是the last bus, 而不是we)Weather permitting, the football match will be played on Friday. (permitting的邏輯主語是time, 而不是the football match)Step 7 Practice1. ________(study) hard, you are sure to get first prize. 2. People use plastic in their daily life, _______(leave) large amounts of waste. 3. ________(work) hard at your lessons, you are to succeed. 4. The old man, ____________(work) abroad for twenty years, is on the way back to his motherland. 5. ______________(finish) his homework, he was playing on the playground. Answers: 1. Studying 2. leaving 3. Working 4.having worked 5. Having finishedStep 8 HomeworkFinish the homework on Page 22.
新人教版高中英語必修3Unit 2 Morals and Virtues-Listening &Speaking＆Talking教學設(shè)計
Example:One day, a poor boy who was trying to pay his way through school by sending newspapers door to door found that he only had one dime(一角）left. He was so hungry that he decided to beg for a meal at the next house.However, he lost his nerve when a lovely young woman opened the door. Instead of a meal he asked for a drink of water. She thought he looked hungry so she brought him a large glass of milk. He drank it slowly, and then asked, “How much do I owe you?” “You don’t owe me anything,” she replied, “Mother has taught me never to accept pay for a kindness.” “Then I thank you from the bottom of my heart.” With these words, Howard Kelly left that house.Years later the woman became badly ill and was finally sent to the hospital in a big city. Dr. Howard Kelly, now famous, was called in. When he heard the name of the town she came from, a strange light filled his eyes. Dressed in his doctor’s clothes, Dr. Kelly went into her room and recognized her at once. From that day on, he gave special attention to her, and decided to do his best to save her life.At last the woman was saved. Dr. Kelly asked the business office to pass the final bill to him. He looked at it and then wrote something on the side. The bill was sent to the woman’s room. She was afraid to open it because she was sure that it would take the rest of her life to pay for it off. Finally she looked, and the note on the side of the bill caught her attention. She read these words: “Paid in full with a glass of milk, Dr. Howard Kelly.” Tear of joy flooded her eyes.
新人教版高中英語必修3Unit 2 Morals and Virtues-Reading for Writing教學設(shè)計
1. 這個寓言是一個關(guān)于一位國王古寓言。 The fable is an old fable about a king.2.作者用這個故事讓讀者對于社區(qū)的問題負有個人責任的必要印象深刻。The author used the story to impress upon readers with the need to take personal responsibility for problems in the community.3. 這個故事十分成功的實現(xiàn)了它的目的。The story was quite successful in achieving its purpose.Step 7 WritingPlease write a review of the story according the outline above.The fable is an old fable about a king who thought his people are lazy, so he put a large stone in the middle of the road and hides and waited to see if anyone will try to move it.The author used this story to impress upon readers with the need to take personal responsibility for problems in the community. The story was quite successful in achieving its purpose, and I liked it because it had a clear moral.However, while the moral of the story is clear, the actions of the king seemed pointless to me, because none of the characters in the story learnt anything. For this reason, I think there are better stories that can be used to impress upon people with the need for personal responsibility.Step 8 Pair workExchange drafts with a partner. Use this checklist to help your partner revise his/her draft.1. Does the writer give a short description of the story ?2. Does the description include the most important details of the story ?3. Does the writer give his or her opinion about the character or their actions ?4. Is the review well-organised ? 5. Does the writer use the -ing form as the adverbial correctly in the writing ?6. Are there any grammar, spelling, or punctuation errors ?Step 9 HomeworkPut up your revised draft in the classroom or read it to your class.
新人教版高中英語必修3Unit 3 Diverse Cultures-Reading and Thinking教學設(shè)計
Discuss these questions in groups.Q1: Have you ever been to a place that has a diverse culture ? What do you think about the culture diversity ?One culturally diverse place that I have been to is Harbin, the capital city of Heilongjiang Province. I went there last year with my family to see the Ice and Snow Festival, and I was amazed at how the culture as different to most other Chinese cities. There is a big Russian influence there, with beautiful Russian architecture and lots of interesting restaurants. I learnt that Harbin is called “the Oriental Moscow” and that many Russians settled there to help build the railway over 100 years ago.Q2: What are the benefits and challenges of cultural diversity ?The benefits: People are able to experience a wide variety of cultures, making their lives more interesting, and it can deepen the feelings for our national culture, it is also helpful for us to learn about other outstanding culture, which helps improve the ability to respect others. The challenges: People may have trouble communicating or understanding each other, and it may lead to disappearance of some civilizations and even make some people think “The western moon is rounder than his own.”Step 7 Post reading---RetellComplete the passage according to the text.Today, I arrived back in San Francisco, and it feels good (1) _____(be) back in the city again. The city succeeded in (2)_________ (rebuild) itself after the earthquake that (3)________ (occur) in 1906, and I stayed in the Mission District, enjoying some delicious noodles mixed with cultures. In the afternoon, I headed to a local museum (4)____ showed the historical changes in California. During the gold rush, many Chinese arrived, and some opened up shops and restaurants in Chinatown to earn a (5)_____ (live). Many others worked on (6)______ (farm), joined the gold rush, or went to build the railway that connected California to the east. The museum showed us (7)____ America was built by immigrants from (8)________ (difference) countries and cultures. In the evening, I went to Chinatown, and ate in a Cantonese restaurant that served food on (9)________(beauty) china plates. Tomorrow evening, I’m going to (10)__ jazz bar in the Richmond District. 答案：1. to be 2. rebuilding 3. occurred 4. that 5.living6. farms 7.how 8. different 9. beautiful 10. a
新人教版高中英語必修3Unit 4 Space Exploration-Listening&Speaking&Talking教學設(shè)計一
Listening and Speaking introduces the topic of “talking about how to become an astronaut”. This period is aimed to inform students some details about the requirements of being an astronaut. Students can be motivated and inspired by the astronauts. Teachers ought to encourage students to learn from them and let them aim high and dream big.Listening and Talking introduces the theme of "talk about life in space". This part also informs students more details about life in space and can inspire students to be curious about this job. 1. Guide students to listen for numbers concerning dates, years and ages etc2. Cultivate students' ability to talk about how to become an astronaut and life in space ; 3. Instruct students to use functional sentences of the dialogue such as “ first of all, I am not sure, so what might be .. I guess.. I wonder…I am curious…)appropriately.1. Guide students to understand the content of listening texts in terms of the whole and key details; 2. Cultivate students' ability to guess the meaning of words in listening; discuss with their peers how to become a qualified astronaut and describe the life in space.Part 1: Listening and SpeakingStep 1: Lead inPredictionThe teacher can ask students to predict what the listening text is about by looking at the pictures.About how to become an astronaut./the requirements of an astronautStep 2: Then, play the radio which is about an interview a. And after finishing listening for the first time, the students need to solve the following tasks.
新人教版高中英語必修3Unit 4 Space Exploration-Discovering Useful Structure教學設(shè)計
The theme of the section is “Describe space facts and efforts to explore space”. Infinitives are one of non-finite verbs, as the subjects, objects, predicative, attributes and adverbials. This unit is about space exploration, which is a significant scientific activity, so every scientific activity has strong planning. Therefore, using the infinitives to show its purpose, explanations or restrictions is the best choice.1. Learn the structure, functions and features of infinitives.2. Learn to summarize some rules about infinitives to show purpose and modify.3. Learn to use infinitives in oral and writing English. 1. Learn the structure, functions and features of infinitives.2. Learn to summarize some rules about infinitives to show purpose and modify.3. Learn to use use infinitives in oral and writing English.Step 1 Lead in---Pair workLook at the following sentences and focus on the italicized infinitives. In pairs, discuss their functions. 1. I trained for a long time to fly airplanes as a fighter pilot..(作目的狀語)2. As we all know, an astronaut needs to be healthy and calm in order to work in space..(作目的狀語)3. First of all, you must be intelligent enough to get a related college degree..(作目的狀語)4. Some scientist were determined to help humans realise their dream to explore space..(作定語)5. On 12 April 1961, Yuri Gagarin became the first person in the world to go into space..(作定語)Summary:1. 不定式的結(jié)構(gòu)：to+do原形。2. 分析上面的句子，我們知道在描述太空探索時，動詞不定式不僅可以用來表目的，還可以用來作定語，表修飾。
新人教版高中英語必修3Unit 4 Space Exploration-Reading and Thinking教學設(shè)計一
Q4: What is the function of the International exploration ?Having astronauts from different countries on boardQ5: What can you learn from Para 4 ?China has made great achievements in exploring spaceQ6: What is the attitude to the space exploration ?SupportiveStep 6 Post reading---RetellPeople have always wanted to learn more about space. Before the mid-20th century, most people felt (1)_________ (travel) into space was an impossible dream. However, (2)____ the help of scientists, peoplesucceeded in realizing their dream (3) _________ (explore) space. On 4 October 1957, the Sputnik 1 satellite (4) ____________(launch) by the USSR. (5) ________________ scientists try to make sure nothing goes wrong, accidents can still happen. These disasters made everyone(6)___________(disappoint), but people still believe in the importance of (7) ________(carry) on space exploration. In 2003, China became the third country to (8)_____________ (independent) send humans into space. Then Shenzhou 6 and 7 completed (9)____ second manned orbit and the first Chinese spacewalk. In spite of the difficulties, scientists hope future (10)__________ (discovery) will not only enable us to understand the universe but also help us survive well into the future.Answers: 1. travelling 2. with 3. to explore 4. was launched 5. Although6. disappointed 7. carrying 8. independently 9. a 10. discoveriesStep 6 Post reading---Critical thinkingQ1: What do you think of the space exploration ? I think it is beneficial to us. Through further study of space, people will make full use of it in the future, such as the space experiments by Wang Yaping in Tian Gong 1.Q2: If you are determined to be an astronaut, what should you prepare at present ?First of all, I should study hard to get a related college degree. Besides, I must keep mental and physical healthy.Step 7. HomeworkTry to summarize the structure of the article by a mind map.
新人教版高中英語必修3Unit 5 The Value of Money-Reading and Thinking教學設(shè)計一
Everybody wants to get wealth.In today’s material world,making money or becoming wealthy symbolizes a person’s success and capability. Many people just make every effort, pay any price to attain greater wealth. With money,they can buy nice, large apartments in nice neighborhood. With money they can own luxurious cars. Wealth seems to bring all happiness in life.But is wealth the only road to happiness? Not really. There are many things in the world, which are beyond the means of money, such as friendship, love, health and knowledge. People are so preoccupied with struggling for money that they have no time or would not take the time to form or maintain friendship. What happiness can they feel living as lonely miserable creatures without love or friends in the world even if they accumulate tremendous wealth?In my opinion, people can’t do anything without money, but money is not everything. What money will bring you depends on your personal belief and goal in life. If you are kind enough to help others, especially the poor, money is a good thing to you. With it, you can do much more for the benefit of people and your country, and it will add to your own happiness. If you want money just for your own needs, you’ll never be satisfied or happy. In a word,you should have money spent for more people. Only then can money be the source of your happiness.Step 8 Homework4 students in a group, one acts Roderick, one Oliver, one servant and the fourth one acts Henry Adams, then listen to the tape, pay more attention to the difference between American English and British English in pronunciation, stress, tone.
人教版新課標高中物理必修1重力基本相互作用教案2篇
具體過程：先用懸掛法確定重心之后，在板上固定一條細線ab，讓ab穿過重心c點，再在其重心c處拴上細繩提拉，驗證薄板可以水平平衡.如圖3-1-6、3-1-7所示.歸納：物體的重心可在物體之上，也可在物體之外.結(jié)論：規(guī)則均勻的物體重心在其幾何中心；不規(guī)則不均勻的物體重心用懸掛法.例3一個被吊著的均勻的球殼，其內(nèi)部注滿了水，在球的底部有一帶閥門的細出水口.在打開閥門讓水慢慢流出的過程中，球殼與其中的水的共同重心將會（）A.一直下降B.一直不變C.先下降后上升D.先上升后下降先讓學生自己回答，估計很多學生會選擇A；教師提示開始和最終重心的位置，學生很快就能得出正確答案.借機引導學生思考問題要全面.參考答案：在注滿水時，球殼和水的共同重心在球心，隨著水的流出，球殼的重心不變，但是水的重心下降，二者共同的重心在下降.當水流完時，重心又回到球心，故選項C正確.
人教版新課標高中物理必修1重力基本相互作用教案2篇
閱讀教材后總結(jié)：是萬有引力的作用把宇宙中的恒星和行星聚集在一起，組成了太陽系、銀河系和其他星系.力的相互作用遍布我們周圍的一切物體.除此之外還有電荷間的相互作用、磁體間的相互作用，我們把這種力稱為電磁相互作用.【思考與討論】質(zhì)子帶正電，但質(zhì)子（與中子一起）卻能聚集在一起構(gòu)成原子核.你能推測是什么力的作用結(jié)果嗎？攻略一：閱讀教材53頁，師生共同討論、總結(jié).攻略二：網(wǎng)絡(luò)搜索或工具書查閱“四種基本相互作用”，進一步了解概念.結(jié)論：決定物質(zhì)的結(jié)構(gòu)和變化過程的基本的相互作用.近代物理確認各種物質(zhì)之間的基本的相互作用可歸結(jié)為四種：引力相互作用、電磁相互作用、弱相互作用和強相互作用.近代物理的觀點傾向于認為:四種基本相互作用是統(tǒng)一的，物理學家們正在為建立大統(tǒng)一理論而努力.但至今也沒有公認的結(jié)論，望同學們好好學習，為科學事業(yè)奉獻自己的聰明和才智.
【高教版】中職數(shù)學基礎(chǔ)模塊上冊：5.6《三角函數(shù)的圖像和性質(zhì)》優(yōu)秀教案
創(chuàng)設(shè)情景 興趣導入問題 觀察鐘表，如果當前的時間是2點，那么時針走過12個小時后，顯示的時間是多少呢？再經(jīng)過12個小時后，顯示的時間是多少呢？．解決每間隔12小時，當前時間2點重復出現(xiàn)．推廣類似這樣的周期現(xiàn)象還有哪些？ 動腦思考 探索新知概念 對于函數(shù)，如果存在一個不為零的常數(shù)，當取定義域內(nèi)的每一個值時,都有,并且等式成立，那么，函數(shù)叫做周期函數(shù)，常數(shù)叫做這個函數(shù)的一個周期． 由于正弦函數(shù)的定義域是實數(shù)集R，對，恒有，并且，因此正弦函數(shù)是周期函數(shù)，并且 ，， ，及，，都是它的周期．通常把周期中最小的正數(shù)叫做最小正周期，簡稱周期，仍用表示．今后我們所研究的函數(shù)周期，都是指最小正周期．因此，正弦函數(shù)的周期是．
北師大版初中數(shù)學八年級下冊不等式的基本性質(zhì)說課稿
[設(shè)計意圖]節(jié)環(huán)節(jié)的設(shè)置是為了使學生在掌握不等式性質(zhì)的基礎(chǔ)之上，加以拓展的作業(yè)，使課程的內(nèi)容不但能滿足全體學生需求，更能滿足學有余力的學生得到更大收獲，從數(shù)軸上獲取信息來完成填空，從而體現(xiàn)數(shù)形結(jié)合的思想，學生通過參與活動，體會挑戰(zhàn)成功的喜悅，并且他們的求勝心理得到了滿足，沉醉在知識給他們帶來的快感中完成本節(jié)課的學習，（六）課堂小結(jié)最后，凱旋歸來話收獲：通過本節(jié)課的學習，你收獲到了什么？學生們都積極的舉手回答，說出了各種各樣的收獲，比如：1、學會了不等式的三條基本性質(zhì)2、學會了用字母來表示不等式的性質(zhì)3、學生不等式與等式的區(qū)別等等；學生在回答的時候，老師加以評價和表揚并展示主要內(nèi)容；這里教師要再次強調(diào)，特別注意性質(zhì)3，兩邊同乘（或除以）一個負數(shù)時，不等號的方向要改變，數(shù)學思想的方法是數(shù)學的靈魂，這節(jié)課我們體驗了三種數(shù)學思想，一是類比的思想，二是數(shù)形結(jié)合的思想，三是分類討論的思想，
人教版高中政治必修2民族區(qū)域自治制度：適合國情的基本政治制度教案
1、有利于維護國家的統(tǒng)一和安全民族區(qū)域自治以領(lǐng)土完整、國家統(tǒng)一為前提和基礎(chǔ)，是國家集中統(tǒng)一領(lǐng)導與民族區(qū)域自治的有機結(jié)合。增強了中華民族的凝聚力，使各族人民特別是少數(shù)民族人民把熱愛民族與熱愛祖國的感情結(jié)合起來，自覺擔負起捍衛(wèi)祖國統(tǒng)一、保衛(wèi)邊疆的光榮職責。2、有利于保障少數(shù)民族人民當家作主的權(quán)利民族自治地方充分享有自治權(quán)利。自主管理本地內(nèi)部事務，滿足了少數(shù)民族人民積極參加國家政治生活的愿望。3、有利于發(fā)展平等、團結(jié)、互助的社會主義新型民族關(guān)系民族自治地方以一個或幾個少數(shù)民族為主體，同時包括當?shù)鼐幼〉臐h族和其他少數(shù)民族，各族人民和各族干部之間聯(lián)系更加密切，逐步消除了歷史上遺留下來的民族隔閡。4、有利于促進社會主義現(xiàn)代化事業(yè)的發(fā)展自治機關(guān)能夠結(jié)合本民族、本地區(qū)特點，把少數(shù)民族的特殊利益與國家的整體利益協(xié)調(diào)起來，充分發(fā)揮各自的特長和優(yōu)勢，調(diào)動各族人民參加國家建設(shè)的積極性、創(chuàng)造性。
北師大初中數(shù)學九年級上冊比例的性質(zhì)2教案
請寫出 推理過程：∵ ，在兩邊同時加上1得， + = + .兩邊分別通分得： 思考：請仿照上面的方法，證明“如果 ，那么 ”．（3） 等比性質(zhì)：猜想 （ ），與 相等嗎？能 否證明你的猜想？（引導學生從上述實例中找出證明方法）等比性質(zhì)：如果 （ ），那么 ＝ ．思考：等比性質(zhì)中，為什么要 這個條件？三、 鞏固練習：1.在相同時刻的物高與影長成比例，如果一建筑在地面上影長為50米，高為1.5米的測竿的影長為2.5米 ，那么，該建筑的高是多少米？2．若 則 3．若 ，則 四、 本課小結(jié)：1．比例的基本性質(zhì)：a:b=c:d ；2. 合比性質(zhì)：如果 ，那么 ；3. 等比性質(zhì)：如果 （ ），五、 布置作業(yè)：課本習題4.2
北師大初中數(shù)學九年級上冊比例的性質(zhì)1教案
若a，b，c都是不等于零的數(shù)，且a＋bc＝b＋ca＝c＋ab＝k，求k的值.解：當a＋b＋c≠0時，由a＋bc＝b＋ca＝c＋ab＝k，得a＋b＋b＋c＋c＋aa＋b＋c＝k，則k＝2（a＋b＋c）a＋b＋c＝2；當a＋b＋c＝0時，則有a＋b＝－c.此時k＝a＋bc＝－cc＝－1.綜上所述，k的值是2或－1.易錯提醒：運用等比性質(zhì)的條件是分母之和不等于0，往往忽視這一隱含條件而出錯.本題題目中并沒有交代a＋b＋c≠0，所以應分兩種情況討論，容易出現(xiàn)的錯誤是忽略討論a＋b＋c＝0這種情況.三、板書設(shè)計比例的性質(zhì)基本性質(zhì)：如果ab＝cd，那么ad＝bc如果ad＝bc（a，b，c，d都不等于0），那么ab＝cd等比性質(zhì)：如果ab＝cd＝…＝mn（b＋d＋…＋n≠0）， 那么a＋c＋…＋mb＋d＋…＋n＝ab經(jīng)歷比例的性質(zhì)的探索過程，體會類比的思想，提高學生探究、歸納的能力.通過問題情境的創(chuàng)設(shè)和解決過程進一步體會數(shù)學與生活的緊密聯(lián)系，體會數(shù)學的思維方式，增強學習數(shù)學的興趣.
北師大初中數(shù)學九年級上冊矩形的性質(zhì)1教案
解：∵四邊形ABCD是矩形，∴AD∥BC，∠A＝90°，∴∠2＝∠3.又由折疊知△BC′D≌△BCD，∴∠1＝∠2.∴∠1＝∠3.∴BE＝DE.設(shè)BE＝DE＝x，則AE＝8－x.∵在Rt△ABE中，AB2＋AE2＝BE2，∴42＋(8－x)2＝x2.解得x＝5，即DE＝5.∴S△BED＝12DE·AB＝12×5×4＝10.方法總結(jié)：矩形的折疊問題是常見的問題，本題的易錯點是對△BED是等腰三角形認識不足，解題的關(guān)鍵是對折疊后的幾何形狀要有一個正確的分析．三、板書設(shè)計矩形矩形的定義：有一個角是直角的平行四邊形 叫做矩形矩形的性質(zhì)四個角都是直角兩組對邊分別平行且相等對角線互相平分且相等經(jīng)歷矩形的概念和性質(zhì)的探索過程，把握平行四邊形的演變過程，遷移到矩形的概念與性質(zhì)上來，明確矩形是特殊的平行四邊形．培養(yǎng)學生的推理能力以及自主合作精神，掌握幾何思維方法，體會邏輯推理的思維價值.
北師大初中數(shù)學九年級上冊菱形的性質(zhì)2教案
1. _____________________________________________2. _____________________________________________你會計算菱形的周長嗎？三、例題精講例1．課本3頁例1例2．已知：在菱形ABCD中，對角線AC、BD相交于點O，E、F、G、H分別是菱形ABCD各邊的中點，求證：OE=OF=OG=OH.四、課堂檢測：1．已知四邊形ABCD是菱形，O是兩條對角線的交點，AC=8cm，DB=6cm，菱形的邊長是________cm．2．菱形ABCD的周長為40cm，兩條對角線AC：BD=4：3，那么對角線AC=______cm，BD=______cm．3．若菱形的邊長等于一條對角線的長，則它的一組鄰角的度數(shù)分別為 4．已知菱形的面積為30平方厘米，如果一條對角線長為12厘米，則別一條對角線長為________厘米.5．菱形的兩條對角線把菱形分成全等的直角三角形的個數(shù)是（ ）．（A）1個 （B）2個 （C）3個 （D）4個6.在菱形ABCD中，CE⊥AB，E為垂足，BC=2，BE=1，求菱形的周長和面積