Mathematics [1] (mathematics or mathematics) is a discipline that studies the concepts of quantity, structure, change, space and information, and belongs to a formal science from a certain point of view. The following is the measurement courseware of mathematical angle in the first volume of the fourth grade of primary school that I brought to you. Welcome to reading.

Textbook analysis

It is based on the students' initial understanding of the angle and the clear concept of the angle, knowing that the angle is different in size, which lays the foundation for students to learn the classification and drawing of the angle in the future.

Teaching objectives

1. Find out the relationship between the size of the angle and the length of the side and the size of both sides.

2. Let the students know the protractor, and measure the degree of the angle with the protractor to compare the angles.

3. Make students cultivate their observation ability, practical ability and abstract ability through observation, operation, comparison and other mathematical activities, further establish the concept of space and enrich their thinking in images.

Through practical activities, students can gain successful experience and build their self-confidence. Through the situation of life, create a feeling that there is mathematics everywhere in life.

The focus of teaching

Difficulties and key points

Master the correct measurement of angle

New teaching of course type

teaching method

Explain, etc.

training/teaching aid

Courseware, protractor

teaching process

First, review old knowledge and introduce new topics.

1. Students, we learned angles last class. Who will tell the teacher what you have learned?

Please raise your hand and introduce the concept and expression of angle.

We already know that the figure formed by two rays from a point is called an angle. Now, please take out the paper and draw a corner.

Ok, let's sit at the same table and compare, whose horn is bigger? Please raise your hand if you think your painting is big.

4. The teacher also drew two corners here (show courseware 2). Please take a closer look at ∠ 1 and ∠2, which is bigger?

(Give students some time to observe) Raise your hand if you think ∠ 1 is bigger? Raise your hand if you feel ∠2?

I found that everyone raised their hands, and some students hesitated. Students all know that we can measure the length of a line segment with a ruler. Measuring the mass of an object can be called weighing; So what can we use to measure the angle?

6. (Some students say protractor, and the teacher leads the topic directly. In this lesson, we will learn "Angle measurement". (Blackboard: Angle Measurement)

Second, students' independent observation and cooperative inquiry learning

1. Just observe the protractor.

Teacher: Let's look at the protractor. What shape is it? (health: semicircle)

Teacher: What else did you observe on the protractor?

Health 1: I see many lines on it (teacher: these lines are called graduation lines. )

Student 2: I see there are many numbers on it (Teacher: What about these numbers? We call it scale value. Observe these scale values carefully and tell me what you find. )

Student 3: I found that there are two circles in the number above (Teacher: We call them inner circle scale and outer circle scale respectively).

Health 4: I found that the numbers are arranged regularly. ...

Teacher: Let's take a look again. These scales are concentrated in the center of ... what we call a protractor.

(The above dialogue between teachers and students will be adjusted randomly according to the students' answers, and courseware 4 will be presented at any time. The slide shows the protractor and the names of the main parts, and introduces the 0-degree scale line and 90-degree scale line. )

2. Establish the concept of 1.

Teacher: On the protractor, we divide this semicircle into 180 equal parts, and the angle of each part is 1 degree, which is recorded as 1 degree. The "degree" here is the unit of measurement of angle, which is represented by the symbol "0".

(blackboard writing: divide the semicircle into 180 equal parts, and the angle of each part is 1 degree, which is recorded as 1 degree).

Third, students try to measure the angle and explore the method of measuring the angle.

Teacher: Now, let's try to measure the angle of 1 on page 37 of the book. (Students test the angle, teachers patrol)

Teacher: OK, some students have measured the angle of 1. Let's listen to how they measure angles! (Let's talk about the angle measurement method first, and show the courseware to guide students how to measure the angle correctly. )

Teacher: The students all speak very well. In order to facilitate memory, the teacher summed up your method into a nursery rhyme (blackboard writing): center to vertex, zero line to one side, scale to the other side, and distinguish between inside and outside.

(PPT shows and asks students to explain their understanding of this children's song)

Students measure angle 2 to deepen students' understanding of children's songs.

Teacher: Let's look at the method of measuring the angle on the big screen and make a judgment (please use the gesture of "√" or "×"). (Play the courseware in turn)

Teacher: Now, let's look at the five corners on the big screen. Let's take a look at the two corners above. On page 38, please take out your protractor and measure it. See which one can measure quickly and accurately. What did you find?

Health: Both sides are different in length. But they are the same size.

Teacher: In other words, the size of the corner has nothing to do with the length of the painting on both sides of the corner.

(PPT shows that the size of the angle has nothing to do with the length drawn on both sides of the angle. )

Teacher: Does the size of that corner matter? You can take out a protractor and measure the degrees of the lower three angles in the book.

Draw a conclusion from the students' answers: the angle depends on the size of both sides, and the bigger the fork, the bigger the angle.

Fourth, classroom activities.

1. Teacher: Now, let's measure the angle we drew at the beginning of the class again. Let's make a comparison between our deskmates. Who drew the bigger corner and how much?

2. Measure the perspective of life.

Teacher: Let's look at page 38 of the book and do the second question. Let's look at the flag of the Young Pioneers first. Who can estimate the angle 1 in degrees? What about angle 2? What about angle 3?

(Students measure angles and communicate)

Teacher: Let's measure it again. What are the angles 4 and 5 on the pentagram?

Verb (abbreviation for verb) summarizes communication.

1. Teacher: What did you learn through this lesson? Students answer and the teacher makes a brief summary.

Teacher: In this class today, we learn to measure angles, so we can apply them to practice. (Show courseware)

Homework after class: 1. Estimate the degree of each angle on the triangular ruler and measure it again.

2. Find and measure the corner of life.

blackboard-writing design

Angle measurement

Divide the semicircle into 180 equal parts, and the angle of each part is 1 degree, and record it as 1 degree.

Center to apex,

Zero line to one side,

Look at the other side of the scale,

Distinguish between inside and outside.