【正文】 拓展：下節(jié)課老師請你把這杯水中的食鹽與水分離出來，你能想出什么辦法呢？ 板書設(shè)計： 100毫升誰能溶解多少克食鹽 100毫升誰能溶解多少克食鹽我的研究計劃了解其他物質(zhì)在水中的溶解度 課后反思：第五篇：四年級教案四年級上冊Lesson 29 A、Teaching aims:Just speak: Further practice of sentence patterns: May I try them on?Certainly Just read and write: To learn the new words: socks、shoes Let’s learn the songB、Important and difficult points: To talk about the clothes C、Teaching aids: Tape recorderslide projectorpicture cards D、Teaching procedure:Warmup Greeting and free talk: Introduce and revision of some prevision sentence a song: sing it again without looking at the 、Knowledge Teacher take a beautiful box, say: Wow!It’s ’s in it?Let’s open it and and open make a surprise to say h, a put the dress card, to teach the word to write 、Comprehensions Match the hat cap dress with their one of the pupils to the class asks in chorus: What would you like? The students work or group the class to make up a new dialogues in 、Applications Ask several pairs or groups to act the their 、Homework Act the and write the new words in this on the blackboard: Lesson 29socksshoesLesson 30A、Teaching aims:Just speak: To revise the sentences: where’s my ….Here it they 、Just read and write: Practice to listen the clothes Let’s make :To make the cards, prehend and applicant the 、Important and difficult points: To learn the clothes C、Teaching aids: Tape recorderslide projectorpicture cards D、Teaching procedure: Revision: 1)Greetings and free talk 2)Sing a song “We’re happy to play.”3)Ask and answer according to the picture cardsKnowledge: Listen to the story , check the picture’s at the book, to practice the dialogue Play the and point the ’re the tape again, students listen and repeat, in students act the 、Comprehension: Have students working pairs in the usual the pictures to explain the weather 、ApplicationHave students work in pairs in the usual sure that they can tell the weather 、Evaluation To do the workbook Home work:Listen and follow the tape recording of lesson 24Read and write the new words in the on the blackboard: Lesson 30 Where is(are)my …?Here it they are.。）：我們怎樣回答50ml水里能溶解多少食鹽？（看大多數(shù)組溶解多少食鹽？），測量1勺大約是（）克，接下來換算50ml水大概溶解多少食鹽。四、交流和分析研究結(jié)果8’。三、分組實驗5’，開展研究活動。：（邊交流邊完成以上研究計劃）？（滿滿一勺，用尺平刮一下），什么時候加第二勺？加到什么時候不要加了呢？（等溶解后再加第二勺，直到不能溶解為止。記錄完全溶解后的勺數(shù)。三、研究的方法一勺一勺的加，每放一勺用尺刮一下。一小袋鹽。（在課題一杯后加上50ml）二、制定一杯水50ml水里能溶解多少食鹽的研究計劃20’ ，這杯50ml的水里能溶解多少食鹽？ ：2勺、3勺、5勺??：想知道誰的猜測正確，該怎么做呢？，完善研究計劃?！窘虒W(xué)準備】演示實驗用：食鹽、塑料小勺、筷子、燒杯、水分組實驗材料：食鹽1小瓶備用、（亦可每包2克的食鹽10包）、筷子盛50ml水的燒杯水槽天平1。在溶解實驗中能用觀察到的事實與他人進行交流，并在制定計劃和實驗操作中感受科學(xué)探究的嚴謹。過程與方法：學(xué)生能設(shè)計“一杯水能溶解多少食鹽”的實驗，并能根據(jù)計劃開展研究，學(xué)會運用數(shù)據(jù)作出解釋。（注意引導(dǎo)學(xué)生反思實驗過程中的不足）。）（3）請一組演示其中一個對比實驗，其余學(xué)生觀察評議確保每組都能正確操作。教師板書相同條件和不同條件。）（1）小組討論：怎樣利用實驗來驗證自己的假設(shè)（每組設(shè)計一兩個實驗來證實自己的猜想）。二、加快方糖溶解的研究：一塊方糖在水中溶解的快慢受哪些因素的影響呢？ ：用攪拌的方法可以使肥皂溶解得快；熱水比冷水更容易使肥皂溶解；將肥皂切成小塊更容易溶解；加更多的水使肥皂溶解得快??3．制定實驗設(shè)計。）。（教師指導(dǎo)對比方法），交流想法?！窘虒W(xué)過程】一、哪一個溶解的快。體驗研究影響溶解快慢因素