1, knowledge and skills: knowing 1 km = 1000 m, you can use the simple conversion of km and m to cultivate the ability of spatial imagination in observation and practice.

2. Process and method: Experience the length of 1 km through activities such as "hand in hand", "thinking" and "walking". The spatial representation of kilometers is initially established.

3. Emotion, attitude and values: Feel the close connection between mathematics and life, and further understand the value of mathematics.

Key points and difficulties:

1, how long does it take to experience a kilometer?

2. Form a perceptual knowledge of how long a thousand meters is through experience activities.

Teaching process:

First, create situations and introduce new lessons.

Students, we have learned many units of length before. What are they?

What letters are they represented by? (Refers to students' answers: meters, decimeters, centimeters, millimeters and books on the blackboard. )

Teacher: That's good. Then who can draw the approximate length of 1 m, 1 decimeter, 1 cm, 1 mm by hand? (Students use gestures to indicate the length of 1 m, 1 cm, 1 decimeter and 1 mm respectively. )

Teacher: Who else knows the progress between them?

Teacher: When measuring or describing relatively short lengths, we usually use meters, decimeters, centimeters and millimeters. So what units do we usually use when measuring longer units of length? In this lesson, let's learn how long 1 km is (blackboard writing).

Second, explore new knowledge.

Teacher: In your impression, how long do you think 1 km is?

Health: I think 1 km.

You have to go to Yangpingguan Town.

Health: 1 km

Yes 1000.

1 meter.

Health: That's 10 meter.

Right, teacher?

Teacher: Yes, you speak very well. 1 km is 1000 block 1 m, and it is also 100 block 100 m long. Then who can tell you how many meters 1 km is?

Health: 1 km is of course1000 m.

Teacher: How clever. Which student can draw the length of 1000m by hand?

Health: Ah! Teacher, I can't.

The students are trying to figure out how to understand how long 1000 meters is.

Teacher: Do you want to go to the playground to experience it yourself? Then listen to Mr. Shang's request and let's go for a walk on the playground. In order to save time, the teacher measured the distance of 10 meter for each group on the playground before class. We take the group as a unit, and the group leader should take notes to see how many steps you can take and how long it takes. Pay attention to walking naturally when you walk, and don't take big steps on purpose, okay? ) Let's walk quietly to the playground and don't disturb others in class. Can we do that? Lead the students to walk on the playground, guided by the teacher, and the team leader should take notes.

(1) Take a walk: Experience 100m.

How long has it been?

1. On the playground, please ask three children to stand in a row hand in hand, and then ask the fourth child to measure and report the measurement results to everyone.

2. Think about it: several students stand hand in hand in a row, which is about 10 meter.

Dragon? Ok 10 meter

Long distance.

Take a walk; /kloc-how many steps do you need to take for the distance of 0/0 meter? (hint: the steps should be as big as when walking normally, neither too big nor too small. )

3. How many students stand in a row hand in hand is about 100m.

? Measurement 100 meter

The length of.

Take a walk. How many steps does it take to get to 100 meters? Sign after leaving

Teacher, help you record the time you need.

(2) Estimation: estimated 1km.

How long has it been?

1, back to the classroom. We have detected 100 meter.

Think about it: 10 100 meters.

How many meters is it? 1000m

Or 1 km.

. This is also the new unit of length that we want to know today-kilometer.

2. Report the results and compare them. And complete the form.

The number of meters

10 meter

100 m

1000m

Number of steps taken

Time spent

How many students are holding hands?

3. Report after group communication: You can talk about the activity just now. 1 km.

About how long? .

① 10 100m；

②10010m;

③ It takes about 20 minutes to walk 1 km;

(4)1000 m how many steps can I take?

⑤ The school playground runway has a circle of 400 meters, with two and a half circles 1000 meters.

⑥ A 50-meter runway is 1000 meters after 20 laps.

……

4. Teacher's summary: 1km

=1000m

Or 1 km

=1000m

(1)1km =1000 m, which sounds difficult to distinguish. Who can skillfully use pause to distinguish between kilometers and meters, let people understand at once.

1 (suspended) km = 1000 (suspended) m

Introduction: Pay attention to the appropriate pause between numbers and units.

Students try to read together, read together.

(2) Explanation: Kilometers, also called kilometers, can be represented by the letter km. Think about it, how is the relationship between kilometers and meters expressed in letters? Name the board of directors.

(3) Estimate (required 1km.

Reference time) and I know

1. Is the distance from home to school 1 km?

Do you know the place about 1 km from there?

Do you know when to use "kilometer" as the unit of length? Students report freely, and teachers demonstrate courseware in time.

4. Teacher's summary

When representing a long distance, use "kilometers" as the unit. Arrange the learned length units in descending order and talk about the relationship between them. What is the difference between 1km and 1000m? Like what?

Third, summary.

What did you learn from this course?

Let the students talk about their gains in this class.

B.how do you evaluate your performance? Tell me which group performed it.

Requirements: After class, the team leader is responsible for adding points according to each student's performance in the group evaluation form.

Fourth, practice design.

Basic exercises

Page 37 of the book

1. Completed, why choose this unit?

2. How do you feel after filling it out?