We know centimeters and meters. How long is 1 cm? Please compare it by hand.

How long is 1 meter? Please stretch your arms and compare them.

(The students stood up and gestured, and the teacher took the meter ruler to patrol among the students and found that there was a big error to be corrected. )

Second, the actual measurement of classroom items.

1. Do you want to know how high the desks we use every day are?

Please estimate the approximate length of your desk. Tell your deskmate the result of the estimation, and then you two can test it together to see who can estimate accurately. (Student activities)

2. After the activity, please report the results of estimation and measurement.

3. Ask the students with accurate estimation to introduce the estimation method to the students.

(Instruct students to evaluate other students' estimation methods during the reporting process)

What is the height of the table you measured?

Tell me how you measured it.

5. After the activity, report collectively.

Compare groups measuring the same object length to check whether the measurement is accurate. )

Third, find and use your own measuring tools.

Students, in fact, we also have many rulers on us. Let's find our own ruler, shall we?

Please measure your height.

(1) What does height mean? (Height from sole of foot to top of head)

(2) estimate first, then calculate. You can measure by yourself or cooperate at the same table.

(3) Talk about measurement methods.

2. Measure your own steps.

What does (1) step mean? Toe to toe or heel to heel distance. )

Emphasis: Step size is the length of one step at ordinary times. Don't deliberately take big steps.

(2) Estimate the length of one step before measurement. You can work in groups.

(3) Who is the most accurate? Please introduce this method to students.

(4) How did you measure it?

3. When the hand is flat, measure the distance between the fingertips.

4. Use your ruler to estimate activities.

Just now, the students measured their height, stride and the distance between their fingertips when their hands were stretched horizontally. In fact, these are all good rulers. Next, the teacher will check whether your ruler tube is easy to use.

(1) Ask two students to come to the front and ask them to estimate his height and tell us how to estimate it.

(2) Estimate the waist circumference and head circumference of these two students.

Do you know what waist circumference and head circumference are?

Please estimate the waist circumference and head circumference of two students. How do you estimate it?

Now I want to know the exact length of waist circumference and head circumference of these two students. How to measure them? Who has a better way?

(3) Use step size to carry out estimation activities.

You know your own step, please take this line as the starting point, estimate where 10 meter will go, and make a mark yourself.

② Take another walk and see how many steps it takes for this 10 meter? Looking at such a long distance, please estimate how many students need to hold hands to reach 10 meter. Who wants to have a try?

What do you think of through these activities? Can you estimate the length of the object correctly?

5. Introduce the common sense of the length relationship between different parts of the human body.

Fourth, practice.

1.P 18 question 2.

(1) Look at the picture. Do you think it's weird?

(2) Ask the students to estimate the heights of Xiaoming and Smart Dog respectively, and talk about how you estimate them.

(3) Guide students to pay attention to the method of recording.

2.P 19 question 3.

(1) Look at the picture to understand the meaning.

(2) Students communicate independently.

Verb (abbreviation of verb) summary.

What did you learn from this course?

Chapter II Teaching Objectives:

1. Can choose a suitable unit to express the length, and will use a measuring tool to measure it.

2. Be able to estimate the length of the surrounding objects, initially form the estimation consciousness, and cultivate students' application consciousness.

3. Enhance students' sense of cooperation and inquiry.

Teaching emphases and difficulties:

1. By guiding students to estimate the length of the surrounding objects and then actually measuring them, they can further learn to use measurement.

2. Measuring tools, choose appropriate length units, and cultivate application awareness.

Teaching process:

First, create suspicion.

1. What units of length have we learned before? What is the relationship between them?

① Length unit: meters and centimeters

② 1m = 100cm 1m = 100 \

Today, Mi and Cm came to make friends with us again. I want to know about the students' mastery and application of them, and see if you can correctly apply Mi and Cm to estimate and measure the objects around you. For example: the length of the blackboard, the height of the table.

Second, interactive solutions.

1. How long is the blackboard?

(1) estimation.

2 meters, 3 meters, 5 meters ...

(2) To measure a quantity, whose estimate is more accurate?

③ Measure in groups and report the results.

Tell me how it is measured.

3. What should I pay attention to when measuring?

The ruler is not long enough when measuring. After measuring once, draw a full stop, count several times, how much is left, and finally get the result.

Third, inspire and guide doubts.

1. Measure your height and stride.

(1) Estimate first, and then cooperate at the same table.

② Exchange and discuss.

Complete the attempt

① Estimate first.

② Measure again.

(3) finally fill in the specific values.

Fourth, practical application.

1. Fill in ""or "=" in ○.

① 25cm ○ 2m ② 100cm ○ 1m

③ 5 1cm χ 49cm ④ 98cm χ 89cm

⑤ 1cm 1m⑤ 1cm 1m

⑦ 33cm, 3m, 8m, 6m and 600cm.

2. Fill it in.

① 1m =()cm② 12m+7m =()m。

③ 13cm+8cm = () cm。

④ 2m+45cm = () m () cm

(5) A small number of objects can be used as a unit ().

6. For larger objects, you can use () as the unit.

Verb (abbreviation of verb) summary and evaluation

What did you learn from this course?

Blackboard Design: Evaluation and Measurement

Estimate first and then measure.

Not a whole meter, the rest are centimeters.

Article 3 Teaching objectives:

1. Through estimation and measurement, further cultivate students' spatial concept, learn to measure the length of some objects, and cultivate estimation consciousness and hands-on operation ability.

2. Through practice and discussion, students can express the length of an object in a certain length unit and establish a more accurate concept of length in their minds.

3. Create an inquiry learning environment for students, so that students can get exercise in cooperative inquiry and enhance their awareness of cooperative inquiry.

4. Let students feel the joy of success in various games and further stimulate their interest in learning.

Teaching emphases and difficulties:

Through practice and discussion, students can express the length of an object in a certain length unit and establish a more accurate concept of length in their minds.

Teaching preparation:

rule

Teaching process:

(a) Activity 1: Create a situation and actually measure the objects in the classroom.

Teacher: Today, we came to the newly-built multimedia classroom in our school for class. How do you feel?

Teacher: The desks, blackboards and platforms here are different in length, width and height from those in our classroom. So, how long, how wide and how high are they? Who wants to estimate?

Teacher: Then let's measure it! We are a team. You can measure anything in this classroom. Discuss and decide what your group will measure first, then estimate how long it will take, then talk about how to measure it, and finally record the measurement results.

(Students measure separately. )

Teacher: Now, it's time to exchange reports. Which group representative will speak first?

Teacher: Is there a blackboard testing team? Is it the same as the result measured by their group?

Teacher: Can you tell me how to write this meter 3? Can you show me how you record it?

(The projector shows the scores recorded in the students' exercise books: 1m3cm, 1 m3 cm, 1.3m)

Teacher: Are there any other groups that measure the length of desks?

Teacher: Come on, can you also show the results recorded by your group?

(The projector shows different recording methods from the previous group: 130cm, 1m3. )

Teacher: There are many ways to record. Can someone make a brief comment?

Teacher: Actually, among these representations, except 1m3cm is incorrect, all other representations are acceptable, and you can choose according to your own knowledge when using them.

Teacher: Then let's measure it again and see how high this door is! Who can give an idea, how to see how many centimeters more? How should it be measured?

The teacher and the students measure together. )

Teacher: It seems that your estimate is quite accurate. The height of this door is 2m 10cm. Then I stood by the door. Can you estimate how tall I am?

Teacher: You are very observant. You haven't let go of the action I just measured.

Teacher: Comparative method is a common method in estimation. It is also a good way for you to judge the height of a teacher by the height of your mother.

Teacher: Just now, when we were measuring, we used measuring tools such as meter ruler, soft ruler and small ruler, which can help us know the length of an object quickly.

(2) Activity 2: Find and use your own measuring tools.

Teacher: When you need to measure the length of an object, there is no ready-made measuring tool around you. what are you going to do？ Do you know that there are many such tools hidden in your body? Although they are not as accurate as rulers, they can help us in many cases!

Teacher: Do you have any other rulers on you? Just now that classmate used her mother's height as a standard to judge the teacher's height, which is a good method. In fact, my height is also a good ruler! Next, let's find our own ruler, shall we?

Teacher: Now I'll assign tasks. Please measure your height, stride length and the distance between your fingertips when your hand is stretched horizontally. You can test it yourself or ask your classmates to cooperate.

Students measure themselves or cooperate with each other, and fill in the measurement results in the book. )

Teacher: Have you measured it? Let's see if your ruler tube works. I invited two students from our class to come to the front. Please estimate their height.

(Two students come on stage at the same time. )

Teacher: Then estimate the waistline and head circumference of these two students. Do you know what waist circumference and head circumference are?

Teacher: You can take your ruler as the standard. Fee courseware. What FFKJ.Net said in Garden is very reasonable. I think your estimate should be more accurate. Now I want to know the exact length of your waistline and head circumference. How to measure? Who has a better way?

(Students measure. )

Teacher: Compare your measurement results with the results you just estimated. What can you find?

Teacher: It seems that these rulers on us really work. Let's try again. You know your steps, please take this line as the starting point, estimate where 10 meter will go, and make a mark yourself.

Teacher: Let's walk again and see how many steps it takes to 10 meter. Looking at such a long distance, please estimate how many students need to hold hands to reach 10 meter. Who wants to have a try?

Teacher: What do you think of through these activities? Can you estimate the length of the object correctly?

Teacher: That's very kind of you. This is how knowledge and ability are accumulated through practice in daily life. I hope you consciously do more exercise in your daily life and be a person with a conscience in life.

(3) Activity 3: Practice

Teacher: Let's do a little exercise about this. Please open the book on page 19 and read the third question. Can you understand? Who can talk about it?

Teacher: Then finish it yourself!

(Students do it independently. )

(4) Activity 4: Summary

Teacher: What did you learn from this class?

Blackboard design:

Simple estimation and measurement