第二单元

Unit two

Campus Art Festival -- The Meaning and Sex of Fractions

(校园艺术节——分数的意义和性质)

Lesson one

1. Divide 1 piece of red play-dough equally among 4 people. How much of this piece of play-dough should each get?

把1块红色橡皮泥平均分给4人，每人分得这块橡皮泥的几分之几？

2. Divide four pieces of black play-dough equally among four people. How much of the play-dough should each get?

把四块黑色橡皮泥平均分给4人，每人分得这些橡皮泥的几分之几？

3. Divide 1 piece of plasticine into 4 equal parts. 1 part is a quarter of it.

把1块橡皮泥平均分成4份，1份是它的四分之一。

4. Think of the four pieces of plasticine as a whole, and divide them into four equal parts, so one of these pieces is a quarter of the whole.

把4块橡皮泥看作一个整体，平均分成4份，1块占这样的1份，是这个整体的四分之一。

5. What do you know?

你知道什么了？

6. What other questions can you ask?

你还能提出什么问题？

7. Divide 4 sheets of yellow paper equally between 2 people. How much of the paper should each person share?

把4张黄色纸平均分给2人，每人分得这些纸的几分之几？

8. How about dividing the six green sheets equally among three people?

把6张绿色纸平均分给3人呢？

9. Use the tools and you'll know.

用学具分一分就知道了。

10. Each of them has two, so why is one represented by a half and one represented by a third?

每份都是两张，为什么一个用二分之一表示，一个用三分之一表示呢？

11. Divide the unit "1" into equal parts to represent such a number or parts, called a fraction.

把单位“1”平均分成若干份，表示这样的一份或者几份的数，叫作分数。

12. A number that represents one portion is called a fractional unit.

表示其中一份的数，叫作分数单位。

13. Just paint it. Think about it. How many categories can you divide these fractions into?

涂一涂，想一想，可以把这些分数分成几类？

14. A fraction whose numerator is smaller than its parent is called a true fraction.

分子比分母小的分数叫作真分数。

15. A fraction whose numerator is greater than its parent or whose numerator and denominator are equal is called an improper fraction.

分子比分母大或分子和分母相等的分数，叫作假分数。

16. An improper fraction of a numerator that is not a multiple of the denominator can also be written as a combination of an integer and a true fraction, usually called a mixed fraction.

分子不是分母倍数的假分数还可以写成整数与真分数合成的数，通常叫作带分数。

Lesson two

1. It took one meter of wool to make four stickers.

做4幅粘贴画用了1米长的毛线。

2. How many meters of wool are used in an average painting?

平均每幅画用多少米毛线？

3. Divide one meter of wool into four equal parts, each a quarter of a meter.

把1米长的毛线平均分成4份，每份是四分之一米。

4. How many disks are used in an average painting?

平均每幅画用了多少个圆片？

5. What's 3 divided by 4?

3除以4等于多少呢？

6. We do this with the aid of tools.

我们借助学具来研究。

7. Think about it. What's the relationship between fractions and division?

想一想，分数与除法之间有什么关系？

8. What is the relationship between them?

它们的关系可以表示为什么？

9. Can you use letters to show the relationship between them?

你能用字母表示它们之间的关系吗？

10. Can you convert nine quarters of an improper fraction into a mixed fraction?

你能把假分数四分之九化成带分数吗？

11. Based on the relationship between fractions and division

根据分数和除法的关系

12. Think about it. How do you get an improper fraction into a mixed number?

想一想，怎样把假分数化成带分数？

Lesson three

1. How much of the whole page does the picture part of each board occupy?

每块展板的图片部分各占整个版面的几分之几？

2. What is the relationship between these three scores?

这三个分数之间有怎样的关系?

3. Who is the unit "1"?

把谁看作单位“1”？

4. How do the numerator and denominator of these fractions change? The magnitude of these fractions doesn't change?

这些分数的分子和分母怎样变化，分数的大小不变？

5. When the numerator and denominator of a fraction are multiplied by a number, the magnitude of the fraction remains the same.

分数的分子和分母同时乘一个数，分数的大小不变。

6. Divide the numerator and denominator of a fraction by a number, and the magnitude of the fraction remains the same.

分数的分子和分母同时除以一个数，分数的大小不变。

7. Think about it. Can you multiply or divide the numerator and denominator of a fraction by 0?

想一想，分数的分子和分母能同时乘或除以0吗？

8. Think about it. How does the fundamental property of fractions relate to the property of quotient invariance?

想一想，分数的基本性质与商不变的性质有什么联系？

Lesson four

1. What have you studied in this unit, class?

同学们，本单元你们学习了哪些内容？

2. What's the gain and the confusion?

有什么收获和困惑？

3. What is a fraction?

什么叫做分数？

4. What is the unit "1"? Can you give me an example?

什么是单位“1”？你能举例说明吗？

5. How do fractions relate to division?

分数与除法的关系是怎样的？

6. What is a true fraction? Can you give me an example?

什么叫做真分数？你能举例说明吗？

7. What is an improper fraction? Can you give me an example?

什么叫做假分数？你能举例说明吗？

8. Some improper fractions can also be written as mixed fractions. Please illustrate with examples.

有的假分数还可以写成带分数，请举例说明。

9. Some false fractions can be converted to integers. Please give examples.

有的假分数可以化成整数，请举例说明。

10. What is the connection between the fundamental property of fractions and the property of quotient invariance?

分数的基本性质和商不变的性质有什么联系？

11. Have you gained a new understanding of grades by reviewing them?

通过回顾整理，你对分数是否有了新的认识？

12. Are you satisfied with your studies?

你对自己的学习满意吗？