Lesson 26 Keep the Candle Burning 教学设计

第二课时 Lesson 26: Keep the Candle Burning
重点单词
holder n. 支托物；持有者
shallow adj. 浅的
lighter n. 打火机；点火器
match n. 火柴
v. 相称；相配
examine v. 检查
重点短语
keep...burning, 使……燃烧
use up 用光，耗尽
be made up of, 由……组成
one-fifth 五分之一
重点句子
1.Carefully put the jar over the candle until the top of the jar rests on the dish.
2.Because about one fifth of the air is made up of oxygen, the water rises and fills about one fifth of the jar.
教学难点
学会分数的表达
环节1 新课导入
What’s this？(It’s a candle.)Yes，it’s a burning candle.We will have an interesting class.Can you guess what we will do in this class？There are some things that may be used in an experiment.Do you want to know what will happen？Today we’ll learn Lesson 26：Keep the Candle Burning.
设计意图：利用带来的教具，凭着学生对科学强烈的求知欲和好奇心，学习本课的新词，并鼓励他们表述实验。
环节2
1.Have a discussion with the students about the two questions on the textbook.
2.Collect the answers from the students.
3.Ask the students to listen to the tape carefully.
4.Explain the meaning of the whole text sentence by sentence，help the students remember the main words and the main sentences.
5.Ask the students to read the text by themselves.
6. Do the Exercise 1 and Exercise 2 on the page of 69.
7. Read the Project after class.
8.要点点拨
（1）.Keep the candle burning！让蜡烛燃烧！
keep... burning 使……燃烧。keep sth.(sb.)doing使某物(某人)保持做某一动作状态。
（2）use up用光，耗尽。表示完全，彻底。
（3）one-fifth五分之一。
分数的表达：
分数由分子及分母两部分构成。用英语表达时，分子用基数形式，分母用序数词形式。若分子为1时，则分母的序数词为单数形式；若分子大于1时，则分母的序数词用复数形式。
如：1/3，one third，三分之一；1/5，one fifth，五分之一；3/4，three fourths，四分之三；2/5，two fifths，五分之二
设计意图：让学生能抓住文中重点词汇和句型，善于归纳。
Unit 5 Look into Science
第二课时 Lesson 26: Keep the Candle Burning
keep...burning
use up
be made of
one-fifth
1.Carefully put the jar over the candle until the top of the jar rests on the dish.
2.Because about one fifth of the air is made up of oxygen, the water rises and fills about one fifth of the jar.