第五单元

Unit five

My family has bought a new house - rectangular and square

我家买新房子了——长方形和正方形的面积

Lesson One

第一课

Which is bigger, the dining room or the kitchen?

餐厅和厨房哪个面积大？

What other questions can you ask?

你还能提出什么问题？

Which is bigger, the dining room or the kitchen?

1. 餐厅和厨房哪个面积大？

What is area?

什么是面积？

How do you compare the sizes of areas?

怎样比较面积的大小？

If you put them on top of each other, they still don't make sense. What do you do?

把它们重叠在一起还是比不出大小，怎么办呢？

What shape of graph is more appropriate for measuring the area of the graph?

测量图形的面积用什么形状的图形更合适呢？

Why is it different?

为什么结果不一样呢？

Different units are used to measure the same figure, and the results are inconsistent.

用不同的单位来测量同一图形，结果不一致。

For convenience, uniform area units are required.

为了方便，需要统一面积单位。

Common units of area are square centimeter, square decimeter and square meter

常用的面积单位有平方厘米、平方分米和平方米。

It's a one-centimeter square with sides and an area of one square centimeter, so you could write it as 1 centimeter squared.

边长是一厘米的正方形，面积是一平方厘米，可以写作1cm2。

What surfaces in life have an area of about one square centimeter?

生活中哪些物体表面的面积大约是一平方厘米呢？

Use 1 square centimeter square to measure, sometimes too troublesome, how to do?

用1平方厘米的正方形来量，有时太麻烦了，怎么办呢？

Should we change to a larger unit of area?

是不是应该换大一点的面积单位呢？

The sides are 1 decimeter square, and the area is 1 decimeter square. I could write it as 1dm squared.

边长是1分米的正方形，面积是1平方分米。可以写作1dm2。

It's a square with sides one meter long and an area of one square meter, so we could write it as 1m squared.

边长是一米的正方形，面积是一平方米，可以写作1m2。

Lesson Two

第二课

1. What is the size of the cubicle?

1. 小卧室的面积有多大？

The floor of the cubicle is rectangular in shape.

小卧室地面的形状是长方形。

How to find the area of a rectangle, we study with the aid of tools.

怎样求长方形的面积，我们借助学具来研究。

Can you figure out the area of this rectangle on the right?

你会求右边这个长方形的面积吗？

The area of a rectangle = length × width

长方形的面积=长×宽。

Five times four is 20（ square meters）

5×4=20（平方米）

2. What's the area of the dining room?

1. 餐厅的面积是多少？

The floor of the dining room is square in shape.

餐厅地面的形状是正方形的。

The area of a square is equal to the length of the side times the length of the side.

正方形的面积=边长×边长。

The size of the dining room: four by four equals sixteen square meters

餐厅的面积：4×4=16（平方米）

3. What is the area of the switch in decimeters? How many square centimeters?

1. 开关的面积是多少平方分米？多少平方厘米？

One times one equals one (decimeter squared).

1×1=1（平方分米）

1 decimeter squared =100 square centimeters.

1平方分米=100平方厘米。

4. What is the area of this tapestry in decimeters? How many square meters?

1. 挂毯的面积是多少平方分米？多少平方米？

Ten times ten is one hundred (decimeter squared)

10×10=100（平方分米）

1 square meter =100 square decimetre

1平方米=100平方分米

Lesson Three

第三课

Gypsum line every meter 12 yuan, wooden floor every square meter 85 yuan.

石膏线每米12元，木地板每平方米85元。

The room is 5 meters long and 4 meters wide

房间长5米，宽4米

What questions can you ask?

你能提出什么问题？

Buy gypsum line and wooden floor each need how much money?

1. 买石膏线和木地板各需要多少钱？

How much did it cost to buy the gypsum line? Find the circumference of the ceiling first.

求买石膏线用了多少钱？要先求天花板的周长。

Five plus four times two is eighteen meters.

（5+4）×2=18（米）

Eighteen times twelve is two hundred and sixteen dollars

18×12=216（元）

Answer: buy gypsum line used 216 yuan.

答：买石膏线用了216元。

Beg to buy wooden floor to use how many money, be about to beg the area of the ground first.

求买木地板用了多少钱，就要先求地面的面积。

Five times four is twenty (square meters).

5×4=20（平方米）

Twenty times eighty-five is one thousand seven hundred dollars

20×85=1700（元）

Answer: bought wood floor to use 1700 yuan.

答：买木地板用了1700元。