It can be written as follows: in terms of length, one square kilometer is more than one hectare, and the cardinal number is 100, that is, one square kilometer is equal to 100 hectare. Square kilometers are usually used in relatively large areas, such as cities or forests and oceans. Hectares are mainly used in smaller areas [such as schools and villages]. Each has its own purpose, and usually cannot be used interchangeably.

: 1. Conversion relationship between hectares and kilometers

1 ha = 1 10,000 m2

1 m2 = 100 square decimeter = 10000 square centimeter

1 km2 =1000x1000 =100000 m2.

1km2 =100000 ÷10000 =1000 hectares.

1 ha =0.0 1 km2

The units of the area from small to large are: square millimeter, square centimeter, square decimeter and square meter, and its base is 100.

That is, 100 mm2 = 1 cm2, 100 cm2 = 1 cm2, 100 cm2 = 1 m2.

2. Learning the teaching design of hectares and square kilometers.

1. Teaching objectives:

1) Through actual observation and calculation, get a preliminary understanding of the common unit of land area-hectare, know the actual size of 1 hectare, and establish the representativeness of 1 hectare. 1 hectare =10000m2, simple unit conversion.

2) Experience observation, imagination, reasoning, communication and other mathematical activities, enrich the understanding of hectares, develop the concept of space and improve the awareness of application.

3) Feel the connection between mathematics and life and get a positive emotional experience.

2. Teaching emphasis: Perception of the size of 1 hectare, and simple unit conversion with the progressive rate of hectares and square meters.

3. Teaching difficulties: establishing the representativeness of 1 hectare.

4. Teaching preparation: multimedia courseware guidance plan

5. Teaching process:

1) Review the area unit.

Talk: What units of public area have we learned? Can you tell us from big to new? What is the growth rate between adjacent area units?

2) Reveal the topic: Today we will learn a commonly used unit of land area-hectare (on the blackboard).

6. Explore new knowledge.

1) presents the living materials and preliminarily perceives hectares.

2) Talk: hectares are widely used in our lives. Let's look at a set of materials first. The "Bird's Nest" covers an area of about 20 hectares; Tiananmen Square covers an area of about 44 hectares; Beijing happy valley covers an area of about 56 hectares; Hong Kong Disneyland covers an area of about 126 hectares.