Understanding of Millimeter is the first lesson of Unit 1 of Grade 3 Mathematics in the standard experimental textbook of compulsory education curriculum. The students already know centimeters and meters. This lesson is to continue to learn the length unit millimeter. Examples in the textbook 1 Use activities such as estimation, measurement and discussion to let students know the meaning of millimeters, and then use students' ruler to let students know about millimeters and understand the relationship between millimeters and centimeters. And help students establish the concept of 1 mm through a penny. Doing something, measuring and other activities further consolidated and deepened this part. Learning the content of this lesson well is an important basis for studying length units, estimation and measurement in the future.

Second, the analysis of learning situation

Every student has his own life background, family environment and certain cultural feelings, which leads to different students having different knowledge bases, thinking modes and problem-solving strategies. It is no stranger to the students in this class. Intellectually speaking, it is based on the understanding of centimeters and meters. From the experience, every student's ruler has a millimeter scale. It can be said that we have some perceptual knowledge about this. Therefore, in teaching, I pay attention to let students experience the activities of mathematical communication as much as possible, and let students feel the thinking methods and processes of others in acquiring knowledge.

According to the analysis of teaching materials and learning situation, I have determined the following teaching objectives:

1, let students experience the process of measurement and know the practical significance of millimeters.

2. Know that the unit of length is millimeters. The concept of the length of 1mm is preliminarily established. Knowing the relationship between centimeters and millimeters, we can make a simple conversion.

The length of the object will be measured in millimeters.

4. Cultivate students' observation ability, hands-on operation ability and practical problem-solving ability through independent inquiry and cooperative communication.

5. Cultivate students' preliminary estimation ability and application consciousness.

Teaching focus:

Establish the length concept of 1mm, clarify the relationship between mm and cm, and make a simple conversion.

Teaching difficulties:

Make students go through the process of measurement, understand the practical significance of millimeter generation, and establish the concept of length of1mm. The length of the object will be measured in millimeters.

Teaching process:

First, the introduction of new courses.

(1) Have you measured your height? Who can tell me your height?

What unit do you use to measure your height? Meters and centimeters are the units of length we have learned. You can make a gesture. How long is 1 meter? How long is 1 cm? Do you know the relationship between them?

(2) Before class, the teacher asked each child to take off the school badge. Now, please observe the school emblem carefully. Can you estimate it?

Count its length and width? (Name a few) Is the estimate accurate? How can I know the exact length? Have you measured it before? Think about what to pay attention to when measuring. (One end of the school emblem should be aligned with the 0 scale) Now please measure it quickly!

(Student report) Maybe: Some say 1 cm is wider, while others say it is less than 2 cm wide.

Teacher: That means the width is not a whole centimeter. What if the teacher wants to know his exact length?

(3) Teacher's summary: In fact, in our daily life, there are many small objects whose length is not the whole centimeter. In order to measure more accurately, we must learn the unit of length less than cm-mm. Today, let's learn about millimeters. (blackboard writing topic)

Second, explore new knowledge.

(1) Cognitive millimeter, perceptual length1mm.

1. Can you find millimeters on your ruler? Try it and show it to your deskmate when you find it.

2. Name the projection and find the millimeter. (The teacher enlarges the ruler)

Possibility: A cell is one millimeter.

Teacher: Are you looking for the same thing as him? Congratulations on finding the right one. )

3. Summary: There are many cells in the middle of 1 cm on the ruler, and the length of each cell is 1 mm (referring to any 1 cell), that is, 1 mm, that is,1mm.

In fact, the thickness of our school emblem is1mm. Please feel the thickness. What do you think of 1mm?

(Very short) Now, please hold the school badge like a teacher, and then slowly take it off and observe the distance between your two fingers. What is it like? (A gap)

6. Think about what we are about 1mm long in this life. (Introduction: 50 cents, magnetic cards, etc. )

7. Thinking: What are the objects measured in millimeters in life?

Teacher: When measuring short objects, we should use millimeters as the unit. When more accurate measurement is needed, it is also necessary to use millimeters as a unit.

8. Since millimeters are so useful, let's close our eyes and keep the length of 1mm in our minds!

(2) Understand 1cm = 10mm.

1, Teacher: We know that the square of 1 on the scale is 1 mm, so how many millimeters is 1 cm? Please select any 1 cm on your ruler and count it. (For the convenience and clarity of counting, Xiao Peng points to the numbers with a pencil. ) Count yourself first, and then show it to your deskmate.

2. Did you find anything? (Name: 10 mm in 1 cm) From what date? What is the result of counting? (More than one or two) Is there 10 mm in 1 cm? Teacher Yu will also choose 1 cm. Shall we count together?

3. How's it going? (1 cm is exactly10mm)

4. The teacher writes on the blackboard: 1 cm = 10 mm (once read: backward and forward)

5. Q: So how many millimeters is 2 cm? What about 4 centimeters?

(3) measurement

Teacher: We already know millimeters and the relationship between millimeters and centimeters. Now we will use this knowledge to solve some practical measurement problems.

1, make a P3.

(1) done independently

(2) Exchange reports. How do you know that? How many millimeters are 2 cm and 7 mm?

(3) praise people who fill in the blanks correctly

2. Measure the length of each side (in millimeters)

(1) independent measurement

(2) report by name

Third, consolidate new knowledge.

1, fill in the appropriate length unit.

(1) The length of the pencil is about 18() (5) The length of the chalk is 75 ().

(2) The thickness of a penny is about 1() (6) The distance from Xiao Fang's home to school is 200 ().

(3) The length of classroom is about 8() (7) The length of a key is 45 ().

(4) Lingling's height is 125() (8) The thickness of the exercise book is about 3 ().

2. I can calculate.

50 mm = () cm 76 mm = () cm () mm

3 cm = () mm 100 mm = () cm

4 cm 3 mm = () mm

(4) class summary

Time flies, a class is coming to an end. What did you gain from this class? How many units of length do we know so far? Can you line them up? M-cm-mm. (blackboard writing) The meter is not the unit of length, nor is the millimeter the smallest unit of length. If you are interested, you can look it up in books or online.

Fifth, extracurricular extension.

Change it.

Wednesday, April 18, 2007 Weather: sunny

This morning, I got out of the 2mm bed and went to the bathroom. Brush your teeth with a 15m toothbrush, and rush to school after breakfast. When I came to school, I saw the teacher teaching in the classroom all the time. I quickly took out a 17mm long pencil and an 8m thick notebook and took notes carefully.

Ask students to correct what they think is inappropriate. )