1.重点:学会比较亿以内数的大小。能把整万的数改写用万作单位的数。
2.难点:学会比较位数相同亿以内数的大小。能正确地省略万后面的尾数写出它的近似数。
3.关键:以比较万以内数为基础,把个级比较方法推广到万级,能正确比较亿以内数的大小。把生活中的某些镜头带到学生面前,由果到因,让学生体会近似值在社会生活中的实际应用。
让学生说说这节课的体会,并答解疑难问题。
1.第4题 由师生对答哪些是近似数,哪些是准确数。
2.第5题 由学生自己独立完成,然后开火车的形式校正,并要求说明过程。
3.第7题 由老师提示,讲解题意,然后让学生独立完成,同桌互对。投影校对,并让学生提出质疑。
4.第8题 学生独立完成,拿学生的课本投影校对,并请学生说明理由。
1.复习比较两个数的大小。
师:我们已经学了怎样比较亿以内数的大小,谁来说一说比较大小的方法。(指名1、2个学生回答)
师让学生自己完整的总结:首先要看数位是否相同,相同的数位就要从最高位比起,如果不能比较出来,就一位一位往下比,直到比出大小为止。如果数位不相同,就看哪一个数的数位多那个数就大。
2.复习把整万的数改写成用万作单位的数。
1100000=110万 1210000=121万 720000=72万
师:要写成以万作单位的数就要把万后面的零去掉,要加上一个万字。
3.做一做练习 学生独立完成,全班核对。
Dear XX,
i am very happy to see you,i think you teach very well,we all love you!
i think your english class is better than our old english teacher's class,i believe you can do better than better!i believe in you!
Best wishes to you!
yours,
XXX
XXXX.X.X
Hello, we are XX tourism company, we have you and your 2 children 4 to set up tourist routes for you to choose.
From Beijing to Shanghai's tourist routes, you can go play in Shanghai Zoo, which has its own characteristics is a large-scale integrated Zoo. Then you can also go to Shanghai, Nanjing Pedestrian Street shopping, it is a shopper's paradise.
From Beijing to Changsha tourist routes, you can go play Changsha Window of the World, which is a new development in an amusement park. Then you can go take a look at Pinghu Tang and Wangfujing, one of the very many. Yuelu Mountain is you have to go to a place, from the top you can see the whole Changsha.
From Beijing to Guangzhou's tourist routes, you can go a long long amusement park to play, and that there are many excellent recreational facilities, so that you will not regret it. You can also go to Hong Kong the world's wildlife, which is currently China's largest imitation of the Wild Animal Park. Guangzhou's food is delicious, you will like.
From Beijing to Guilin tourism line, you can go to the famous Lijiang River, sitting on the boat to enjoy the beautiful scenery, and then can go to Yinzi Yan, it was China's first large cavern 4. Guilin Yang Shuo in the line of Yang Renjie shopping and you will be a good place to eat. That you will not feel the same with Chinese characteristics.
I hope you are happy to play China
Yours
XXX
© 2022 xuexicn.net,All Rights Reserved.