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陈雷英语 小学数学 三年级上 查看内容

第九单元

2021-5-31 10:31| 发布者: admin| 查看: 150| 评论: 0

摘要: .
 
Unit 9
I'm a little cook——The preliminary understanding of fractions
我当小厨师——分数的初步认识

Lesson 1
Cooperative exploration
合作探索
1. Each child can get half of the moon cake. How about half?
1. 每个小朋友能分得这个月饼的一半,一半怎样表示?
One half is written as 1/2. It is pronounced as one half
一半用1/2表示,读作:二分之一
2.What does 1/2 mean?
1. 1/2是什么意思?
 Divide a ○ into two equal parts, and one is one half of it.
把一个○平均分成2份,一份就是它的二分之一。
3. Divide a baked cake into 4 equal parts. How much is each piece?
1. 把一个烧饼平均分成4份,每份是多少?
I'm going to use a round piece of paper to represent the pancake, and I'm going to divide it into four equal pieces, so each piece is going to be a quarter of it.It is indicated by 3/8.
我用一张圆形纸片表示烧饼,把它平均分成4份,每份就是它的四分之一,用1/4表示。
4.Divide a cake into eight equally. How much does three equal?
1. 把一个蛋糕平均分成8份,3份是多少? 
I'm going to use a round piece of paper to represent the cake, and I'm going to divide it evenly into 8 pieces, so each piece is one eighth of it, and 3 pieces is three eighth of it.It is indicated by 3/8.
我用一张圆形纸片表示蛋糕,把它平均分成8份,每份是它的八分之一,3份就是它的八分之三,用3/8表示。
Like 1/2, 1/4, 1/8, 3/8...... Numbers like this are all fractions.
像1/2、1/4、 1/8、 3/8......这样的数,都是分数。

分子: Numberator       分数线:fractional line         分母:Denominator

Lesson 2
Xiao Dong ate five eighth of the orange.
小东吃了这个橙子的5/8。
Xiao Li ate three eighth of the orange.
小利吃了这个橙子的3/8。
What questions can you ask?
你能提出什么问题?

合作探索
1.Who eats more, Xiao Dong or Xiao Li?
1. 小东和小利谁吃得多?
Compare the five eighth to the three eighth, and you'll see who eats the most.
比一比5/8和3/8的大小,就知道谁吃得多了。
2. Would you compare the size of the scores in each of the following groups?
1. 你会比较下面每组分数的大小吗?

Lesson 3
Liangliang drinks three fifth of the glass of juice and Lingling drinks one fifth of the glass of juice.
亮亮喝了这杯果汁的3/5,玲玲喝了这杯果汁的1/5。
What questions can you ask?
你能提出什么问题?
Cooperative exploration
合作探索
1. What percentage of the glass of juice did Liangliang and Lingling drink?
1. 亮亮和玲玲一共喝了这杯果汁的几分之几?
three fifth plus one fifth equals to......
3/5﹢1/5=
2. What percentage of the glass of juice did Liangliang drink more than Lingling?
1. 亮亮比玲玲多喝了这杯果汁的几分之几?
three fifth minus one fifth equals to......
3/5-1/5=

Retrospectively review—— general revision
回顾整理 总复习


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