Teaching design of area and area unit
course content
Compulsory Education Textbook (People's Education Edition) Mathematics Grade Three Volume II, Pages 60 ~ 63.
Textbook analysis
"Area and Area Unit" is the first lesson of Unit 5 in the second volume of Grade Three Mathematics published by People's Education Press. This unit belongs to the field of space and graphics, including: area and area unit, area calculation of rectangle and square, and propulsion rate of area unit. This lesson is the beginning of this unit. The length of students' study last semester to the study area this semester is the beginning of the transformation from one-dimensional space to two-dimensional space, and it is a leap from line to surface in spatial form.
Analysis of learning situation
Through the previous study, students have mastered the length and length units, the characteristics of rectangles and squares and the calculation of their perimeters. The study of area is the first contact of students, which is more abstract. Therefore, it is necessary to help them understand the meaning of area by observing the size of familiar surfaces. After understanding the meaning of area, they will further learn the area unit. In addition, judging from the cognitive level of the students in Grade Three, they are in a critical stage of transition from concrete thinking to abstract thinking, and students' knowledge in the field of space and graphics is a process from object to surface to line to point. Therefore, in teaching, we must pay attention to this point, let students experience and feel from life, and gradually reveal the relevant knowledge of area and area unit.
Teaching objectives
1. Let students understand the meaning of area by pointing, touching and comparing.
2. In the process of solving problems, make students experience the necessity of establishing area units and get a preliminary understanding of the law of establishing area units.
3. Know the common area units: square centimeter, square decimeter and square meter. Get the spatial concept about its actual size in the activity and form a correct representation.
4. Cultivate students' observation ability, calculation ability and generalization ability, so that students can realize that mathematics comes from life and serves life.
Teaching focus
? Understand the meaning of area and know the unit of area.
Teaching difficulties
? Establish the correct representations of 1 cm2, 1 decimeter square and 1 m2.
Teaching preparation
1. onion micro-lesson video: understanding area, measuring area and common area units.
2. Square paperboard of 1 cm2,1cm2 and 1 m2.
There are 56 pieces of A4 paper and some cardboard.
teaching process
First, the game import, stimulate interest
1. Stick two rectangular cardboard with obvious size difference on the blackboard, and ask two students to have a coloring contest to see who paints the paper first wins.
2. Question: Is the game fair? Why? This is unfair because the two pieces of cardboard are different in size. )
3. Draw out the topic and write it on the blackboard.
Second, observe and compare, understand the concept
1. Play the onion micro-lesson video: "Cognitive area" (pause to 2 minutes and 5 seconds).
(1) Question: What do you know from the video?
(2) The teacher made it clear that the surface size of objects is called their area.
2. Continue to play the onion micro-lesson video: "Cognitive Zone" (until the end)
(1) Question: Does the video clearly tell us what the area is? (size)
(2) Students observe the blackboard surface and the national flag surface, the students' class desktop and the podium desktop, and talk about which surface is bigger.
(3) We also know from the video that everything has an area except the surface of an object. (closed graph)
3. Teacher's summary: The size of the surface of an object or the size of a closed figure is called their area.
Third, hands-on operation, measuring area.
1. Play the onion lesson video: "Measuring Area".
(1) Question: What did you gain from the video? (When appropriate, you can choose a square as the area unit to measure the area of the graph. )
(2) The courseware shows the process of measuring the area with circular, triangular and square pendulums respectively, and further clarifies that it is more appropriate to choose square as the area unit.
(3) What else does the video tell us? When measuring, there are several squares in the figure, and its area is also several squares. )
2. Complete the "Do" on page 62 of the textbook.
3. Students begin to operate.
(1) Give each person a piece of A4 paper, and students choose a square to measure.
(2) Students report the measurement results.
(3) Question: Why are the measurement results different? (Everyone chooses a different box size. )
Fourth, unify the unit and establish an image.
1. Play the onion micro-lesson video: public area unit (pause to 4 minutes and 37 seconds).
(1) What area units did you learn from the video? How big are they?
(2) the teacher once again clear blackboard writing:
1 cm 2: a square with a side length of 1 cm.
1 square decimeter: a square with a side length of 1 decimeter.
1 m2: a square with a side length of 1 m.
2. Continue to play the onion micro-lesson video: "Public Area Units" (until the end).
3, practice to consolidate:
(1) The cover of the math textbook is about 3 (? )。
(2) The area of a button is about 2 (? )。
(3) The area of the flower bed is about 40 ().
(4) The area of computer display screen is about 8 ().
Verb (abbreviation of verb) practical application and deepening improvement?
(Courseware presentation: intellectual breakthrough)
1. Level 2: I am a small judge.
(1) The area of an eraser is about 8 square centimeters. ( )
(2) The cover area of the math book is about 6 square decimeters. ( )
(3) a square with a side length of 1m and an area of1m. (? )
Level 3: I'll fill it out.
(1) My height is 128. )
? (2) The area of the ground is about 50 ()
(3) The area of a single bed is about 2 ()
(4) The area of a stamp is about 6 (? )
3. Level 4: Mathematics Hospital
After coming home from school, Ma Xiaoha's family was sitting at the square table of 1 m2, and a stone accidentally bit off the front teeth of 1 m2. Suddenly bleeding profusely, Xiao Maha quickly took out a handkerchief of 4 square centimeters, covered his mouth and ran to the hospital 50 centimeters away from home. ...
Sixth, the class summary
Math diary:
Today's math class, I learned (? ) is their area. I know three commonly used units of area: (? )、( ? )、( )。 I see. The nail of our thumb is closest to 1 (? ), the palm of an adult is about 1 (? ), the area of a square table desktop is about 1 (? )。 I must be a serious student and learn to choose the right area unit to measure the area of an object.
Seven. distribute
Complete the textbook "Exercise 14".