Model essay 1 on the design of mathematics teaching plan for the third grade of primary school: understanding graphics
Teaching objectives
Know regular polygons, feel the beauty of combined graphics in life, and explore beauty with puzzles.
Cultivate students' ability of observation and induction.
Emphasis and difficulty in teaching
Know regular polygons.
teaching tool
Teaching courseware
teaching process
Introduction of new lesson
Teacher: "children, the world of fairy tales is really wonderful." Look, today we invited some special friends. Let's get to know them together. "
New curriculum exploration
Query 1
Teacher: "Do you find any characteristics of these friends?"
Health: "There are rectangles, circles, squares and triangles."
Teacher: "Do you know the secret of these figures?"
1: "The four sides of a square are equal, the opposite sides of a rectangle are equal, and a circle has countless symmetry axes."
Health ②: "The four corners of a square and a rectangle are right angles."
…………
Survey 2
Teacher: "Everyone speaks very well. Now there is a mysterious guest. Do you know each other? "
Video: magic carpet
Teacher: "This friend has come all the way from India. Let's get closer and get to know each other. What did you find? "
Health: "Flying carpets are all made up of various figures, including squares, triangles, hexagons and pentagons."
Teacher: "Now all our graphic friends are here. Please classify these friends and explain the reasons. Let's discuss it in groups of four. "
Health ①: "Divided into triangle, quadrilateral, pentagon and hexagon."
②: "According to the characteristics of edges, they can be divided into equal length and unequal length."
Teacher: "If each side is equal in length, these figures are called regular polygons." For example, the five sides of a Pentagon are equal, which is called a regular Pentagon. ..... (If not, please specify. )
Teacher: "What's the secret of these regular polygons?"
Health: "They are all axisymmetric figures."
Teacher: "They have several symmetry axes respectively. Please make a discount and complete the worksheet. "
Teacher: "What are the characteristics of the symmetry axis of a regular polygon passing through the worksheet?"
Health: "The number of symmetry axes of regular polygons is the same as the number of sides."
Survey 3
Teacher: "children, are these characters in life beautiful?" The teacher found some beautiful figures. Look, what are these? "
Displays triangles and quadrangles, followed by a combination of triangles and squares.
Teacher: "Look, this is a new corner designed by Dingding Jr. for his new kitchen. What do you know? "
Health: "It's a combination of triangles and squares."
Teacher: "Kid, what rules did you find when you spelled the ground with two different figures?"
Health: "The length of the edges of two different figures should be the same."
Classroom practice
Exercise 1
Teacher: "Next, let's create beauty, children. You can choose different colors and make a picture with different graphics, or you can make a picture with different graphics prepared by the teacher. Finally, I will introduce it to you in the group. "
Students complete, report and exchange independently, and choose!
Summary after class
Summary of this lesson
What new skills did you learn today?
(1) A polygon with equal length on each side is a regular polygon.
(2) The number of symmetry axes of a regular polygon is the same as the number of sides.
homework
Homework after class
Workbooks on pages 76 and 77.
Model essay 2 on the design of math teaching plan for grade three: area
Teaching objectives:
1, review the area with the number of squares, and calculate the area with the area formula.
2. Through the demonstration of multimedia courseware, students can learn to use the methods of independent inquiry, cooperative communication, observation and comparison, and master the calculation method of irregular figure cutting area. Let students experience the process of knowledge formation and cultivate their innovative thinking.
3. By letting students calculate the area of real houses in life, let students feel the concrete application of mathematics in real life and the close connection between mathematics and real life.
Teaching focus:
Can skillfully use two basic area calculation methods.
Teaching difficulties:
Master the method of cutting and filling graphics to calculate the area of irregular graphics.
Teaching focus:
Connect with real life and learn to calculate the area of real houses in life.
Teaching process:
First, review the old knowledge.
1, review the areas of rectangles and squares.
Show me the rectangle first, then the square. Let's see how big this rectangle is. What is the area of this square? How did you work it out?
summary
You are so clever. You don't need a counting grid. As long as the length and width of the rectangle and the side length of the square are known, the area of the rectangle and the square can be calculated by the area formula.
2. Using the characteristics of translation, semi-lattice rounding and axisymmetric graphics, the figure area parallelogram is found, and the irregular figure is translated into a rectangle, and two semi-lattices form a lattice. As long as half of the axisymmetric figure is calculated and multiplied by 2, the whole figure area can be calculated.
Summary: We can transform parallelogram into rectangle and triangle into rectangle by translation.
Calculate the area of a square. Two semi-grids are merged into one grid, and the area is calculated quickly by using the characteristics of axisymmetric graphics.
Second, new funding.
1. Stimulate interest in learning
The teaching plan of "How big are they" in the first volume of the third grade mathematics of Shanghai Education Publishing House.
Which of these two irregular figures has the largest area?
Which figure has a large area?
Today, this class will specifically study how big their area is.
Irregular graphic area (exhibition topic)
2. Figure A Let's look at Figure A first. Is there any way to calculate its area?
I. Group discussion
B, report various calculation methods
5×4-4
2×5+3+3
4×3+2+2
4×4……
Demonstrate and summarize three methods by computer: digging, filling and moving.
Student: What kind of method do you think? Why?
Cut method: 4×4= 16 and complement method: 5×4-4, these two methods!
The teacher concluded: The fewer blocks or patches, the simpler this method will be.
3. figure b
Figure b is also an irregular figure. Can you find its area in a relatively simple way?
Think independently and then write the results on paper.
Communication: (turn it into a regular figure by complement method)
4×4= 16
The computer demonstration of the method introduced by the students and the calculation formula on the board.
Teacher: Now can we know who is older and who is younger in pictures B and A?
To know exactly which figure has a large area, it is necessary to make a correct calculation, and the simpler the calculation method, the better.
Third, consolidate the practice.
Here are some irregular figures. Please observe them carefully, draw a picture and talk about how to find their areas.
(Communicate independently on the exercise paper)
Say: What's a good way to find a prominent graphic area?
What is a good way to find the concave graphic area?
Conclusion: The fewer blocks or patches, the simpler the method, the better.
abstract
Today, we continued to learn how to find the graphic area. What have you gained?
Model essay 3 on the design of mathematics teaching plan for the third grade of primary school: mixed operation of addition and subtraction
Teaching objectives:
1, understand the calculation method of one-digit and multi-digit multiplication and the mixed operation of multiplication, addition, multiplication and subtraction.
2. Master the multiplication of one digit and multiple digits.
3. Cultivate students' ability to examine questions.
Key points and difficulties:
One-digit and multi-digit multiplication calculation, and finally zero multiplication.
Teaching process:
First, the introduction of new courses.
Show and introduce the carnival to the media.
Ask questions and arouse students' thinking.
Formula: 60×4=240 (blackboard writing)
See if the students are right? (Media presentation)
Second, the exploration of new courses
Query 1
Teacher: "vertical calculation, talk about the calculation process."
Student: "Multiply the number of single digits by 7 first, and then multiply the number of ten digits by 7."
Survey 2
Teacher: "What should I pay attention to when calculating vertically?"
Student: "Put a multi-digit number on it."
Shanghai education publishing house third grade mathematics volume I multiplication and division teaching plan.
Teacher: "Which method is good? Why? "
Health: "The second method is good, as long as you calculate two steps, the first method needs to calculate three steps."
Summary: There is a zero at the end of the factor. First, consider the part before zero as a whole, and then add all zeros at the end of the factor.
Shanghai education publishing house third grade mathematics volume I multiplication and division teaching plan.
Teacher: "Who made a mistake? What's wrong? "
Student: "The tenth 0 of the first classmate is not multiplied by 4."
Summary: When there is 0 in the middle of the factor, don't forget to multiply it.
Survey 4
Analyze the meaning of the problem and calculate continuously.
Teacher: "15×4+ 18, what's first?"
Students: "Calculate first 15×4"
Summary: Pay attention to multiplication before addition in calculation.
Third, practice in time.
Exercise 1
200× 15
Students do it independently.
Teacher: What do you want to remind everyone when you do the problem?
Summary: Be careful not to miss the last zero when calculating vertically. Recursive equation calculation should pay attention to multiplication and division before addition and subtraction.
Exercise 2
1, showing three formulas, which students can complete independently.
Summary: Be careful not to miss the last zero when calculating vertically. Recursive equation calculation should pay attention to multiplication and division before addition and subtraction.
2. Show an equation.
Teacher: Pay attention to multiplication and division before addition and subtraction in recursive equations. Practice one more question and see who can calculate quickly and accurately!
Exercise 3
Tell me what you think.
Column calculation, talk about the calculation process.
Fourth, after-class summary
What did we learn today?
Do you have any questions?
Sheng 1: "Multiplication vertical calculation generally puts a square with more digits on it, starting with one digit."
②: "If there is 0 in the factor, also calculate 0. There is a 0 at the end of the factor, which can be calculated skillfully. "
③: "Recursive equation calculation should be multiplied first, then divided, and then added and subtracted."
…………
Five, after-school exercises
Homework after class
1, vertical calculation
⑴ 8×200 ⑵ 1020×50
2. Recursive equation calculation
⑴ 127×4-239 ⑵ 42+ 158×6