Unit 5 Look into Science.Lesson 26 Keep the Candle Burning.课件

课件16张PPT。They are doing experiments.Do you like doing science experiments? Why? Have you done a science experiment?Lesson 26: Keep the candle burningⅠ. Learning aims: ◆ 知识目标
Master the new words:
match, light, burn, use up, shallow, candleholder, oxygen,one-fifth
2) The important sentences:
① Fill the dish half full of water.
② As the candle burns, it uses up oxygen in the air.
③ There is about one-fifth oxygen in the air, so the water rises and fills about one-fifth of the jar.Ⅱ. 教学重点： 1. Describe and explain the experiment inEnglish.
2.分数的表达法
Ⅲ.教学难点: Describe and explain the experiment in English. ◆能力目标 ：Can describe and explain the experiment in English
◆情感目标：Cultivate the spirit of loving science. 预习早知道
1.match (pl)----__________
light (过去式）___________(过去分词）__________________
burn（过去式）___________ (过去分词）________
use up
one—fifth
shallow(反义词）________
half(pl)______matchesn. 火柴;比赛 lighted/litlighted/litv. 点燃;使燃烧/照亮;使光明burned/t用完；用光；五分之一burned/tdeephalvesLook and Learn
1 .What are they ?They are________ They are used to _______something. I will use them ________a candle. I am _______ the candle with the match. My father often uses matches _______his smoke.
2.This afternoon we’ll have a basketball_______.
matcheslightto lightlightingto lightmatchLook and Learn-----Because burning needs _______. when the candle stops burning, it has ___ ____ all the oxygen in the jar.
They have _______ all the water. ) What’s this? It’s a______ .It’s a _______candle . If I put the jar over the burning candle, what will happen?----It will go out / stop _______ why? candleburningburningoxygenused upused up一. 自主探究，合作学习1.He _____the spoon____the bowl.他把汤匙放到了碗里面。
2.Lily _____the bottle____water. Lily 把瓶子装满了水。
3.The room ___________________ smoking. 屋子里充满了烟。
4.Please put the jar _____the candle.请把罐子放到蜡烛的 上面。
5.My mother________her money to buy clothing yesterday.
我妈妈昨天买衣服花光(用光）了她身上所有的钱。
6.In our class,______ students are boys,______ students are girls. 在我们班，三分之二的学生是男生，三分之一的学生是女生。
二. 小组合作操练，用上述新知识点造句，并在小组 内核对，交流。putinfilledwithis full of/is filled withoverused uptwo-thirdsone-third点拨 Compare and Find分数表达法
分子基
分母序
分子大于 1
分母加 S one - fifth
four – fifths
one - third
two - thirds1/5
4/5
1/3
2/3 基数词序数词分子分母 5/9Practise1/4one-fourth3/7three-sevenths. There is about one-fifth oxygen in the air, so the
water rises and fills about one-fifth of the jar.a quarterfive-ninths强化训练单项选择
1.The bottle is only____full. A.half B.a half C. halfs D.halves
2.She ____the chicken bones to make soup.
A.Used for B. used to C.used up D.used with
3.___of the students in our school____from countryside.(乡村）
A.Four-fifths,comes B.Fourth-five,come C.Four-fifth,come D.Four-fifths,come
4.____of water____. A. Three-fourths, are B.Three-four，is C.Three-quarters，is D. Three-fourth, is
4.The river is _____here; we can walk across.
A. deep B. fast C. shallow
5.Yellow is a _______colour, but black is dark.
A. orange B. light C. heavy
ACDCCBListen,Think ,Read and AnswerWhy did the candle stop burning ?
Because there was no oxygen in the jar .
2. Why did the water rise ?
Because the force outside the jar is stronger than the force inside the jar .
3. How far did the water rise ? Why? It rose about one-fifth of the jar .
Because there is one-fifth oxygen in the air.First, _____the candle ____the candleholder.
Then,_____the candleholder ____the dish.
Third, _____the dish ___________water .
Fourth,______the candle .
Fifth, ______the candle ______for two minutes .
Sixth,carefully____the jar_____the candle
until the top of the jar_____on the dish.
What observation can you make?How do we do the experiment putputininFillhalf full ofLightletburnputoverrestssummaryThe new words:
match, light, burn, shallow, candleholder, oxygen,
The phrases and expressions:
use up, one-fifth, keep sb/sth doing, keep sth/sb +adj
Stop doing/to do sth, put….in/over
分数的表达：分子基，分母序，分子大于 1，分母加 S
Sentences:
① Fill the dish half full of water.
② As the candle burns, it uses up oxygen in the air.
③ There is about one-fifth oxygen in the air, so the water rises and fills about one-fifth of the jar.
How do “ keep the candle burning”
用所给单词的正确形式填空：
1.You are very tired. You’d better stop ______(have) a rest.
2. What do you use to make a candle ________(burn)?
3. You should put the jar over the candle ________(careful).
4. What ______________(observe) can you make?
5. Please cut the apple into __________(half).
6. He __________(light) a candle and the room was bright.
7. He kept the candle _________(burn) for two hours.
8. It’s time ___________(play) basketball.
9. Eating green food can help to keep you ＿＿____ （health）.
10.I’m sorry, I kept you______ (wait) for a long time.to haveburncarefullyobservation(s)halveslighted/litburningto playhealthywaiting1.Read the text aloud and recite the experiment of this lesson.
2. Write “How do …”that you have learned in this unit
3. Preview lesson27.HomeworkClass is over!