Knowledge points of "abdication and subtraction within 20" in first-grade mathematics
Method 1:
"You want to add if you do subtraction" or "you want to add and subtract" is 8+7= 15, so 15-8 = 7, 15-7 = 8.
The calculation method of "doing subtraction and adding" or "adding and subtracting" seems simple, but it requires students' thinking ability. First, students are required to master addition within 20, so as to quickly apply "doing subtraction to add" or "adding and subtracting".
Method 2:
Breaking Ten Law 12-5= 10-5+2=7
The calculation method of "breaking ten methods" is an unpopular method if students are allowed to think about the calculation method themselves. This method can only be mastered by students who study under the guidance of teachers. First of all, tell the students that if 3 is not enough and 5 is reduced, don't reduce it first. Let 10 students borrow 1 into one 10-5, and then the number 5 and the remaining 2 are combined into 7.
Method 3:
Ten-level method14-5 =14-4-1= 9
"Ten-connected method", also known as "continuous subtraction", is characterized by dividing meiosis into the unit of complement meiosis and another number, for example, 5 is divided into 4 and 1, then 14-3= 10, and finally10-1=.
Method 4:
"Less more and more"13-9 =13-10+1= 4.
The characteristic of the method of "subtracting more and adding more" is to subtract the value of subtraction from complement and add 9 to get the number 10, for example, 9+ 1 = 10, and then 13-65438+.
Method 5:
"Add the minuend to a number that can be reduced enough" 13-5= 15-5-2=8.
The method of "adding the minuend to the number that can be reduced" is to add the minuend to the number that can be reduced by the minuend, and then subtract the added number. For example, 13-5 becomes 15-5-2=8, which is easier for students to master.
Knowledge points of "understanding graphics" in senior one mathematics
A, graphics can be divided into (1) plane graphics; (2) Three-dimensional graphics
1. Plane graphics: square, rectangle, triangle, circle, parallelogram.
2, three-dimensional graphics: cuboid, cube, cylinder, sphere.
Second, the combination of graphics.
1, two identical triangles can be combined into a parallelogram; Two identical triangles can be combined into a parallelogram, a rectangle or a large triangle.
2. It takes at least 4 small cubes to form a big cube, and at least 8 small cubes to form a big cube.
3. Two rectangles can form a big rectangle. (Two special rectangles can form a big square), and four cuboids can form a big cuboid.
learning process
1. Teachers lead students to recall the characteristics of three-dimensional graphics.
2. Play the micro video to the students.
(Courseware shows cuboid, cube, cylinder, sphere and triangular prism, and plays the process of "unfolding" plane graphics from three-dimensional graphics)
3. Organize students to draw, draw, print and unfold plane graphics in the exercise book by using learning tools with different shapes prepared before class. Students who draw well and quickly can share his works with Mr. Mai.
4. Know rectangle, square, circle and triangle.
5. Know the parallelogram (guide students to observe the parallelogram composed of two identical triangles)
Teacher: Can you fold a square, rectangle or parallelogram paper into the same two parts? How many folding methods are there? Who wants to tell us how they are folded? What graphics are folded out? Please do it yourself. Students who are prepared can even join Mr. Mai.
6, finishing
(1) courseware presents multiple graphics. Ask the students to tell their parents what each number is.
(2) Say: How do you remember what each figure looks like?
Mathematics learning methods and skills
Plan math activities carefully.
The new curriculum standard especially emphasizes "let students experience the process of summarizing practical problems into mathematical models and explaining and applying them", and attaching importance to the composition process of mathematical common sense is an important concept of mathematical project reform at that time.
In order to let students walk into learning activities with their original common sense and experience, automatically construct and understand mathematical concepts, acquire mathematical methods, thoroughly understand mathematics, and enhance their determination to learn mathematics well,
For example, "Cognition 1 ~ 5", the textbook first shows the general numbers from the international practice, and then lets students further understand the cardinal meaning of numbers by putting a stick; To understand objects and figures, the textbook first improves students' intuitive understanding of the shape of objects by "putting the same figures together", and then the topic that three-dimensional figures lead to the shape of objects appears. Then let students try to describe the date and space of the address with their common sense of mathematics ... In education, we need to plan mathematical activities such as inquiry, operation, thinking and communication for students according to the basic information provided by the textbook and the organization of learning activities, so that students can experience the process of common sense.
For example, in the education of "1 ~ 5 understanding", students have been to parks or zoos, creating a situation of "going to wild zoos". Ask the students to find out which animals they love first, and then let them tell their friends in the group the role of asking and counting, and tell the whole class. After inquiry, statistics and conversation, students generally get 65438+ from the practice of international activities. Next, let the students put out sticks according to the numbers, or choose their favorite school cards. Students refine the general number in their operations and deepen their understanding of the cardinal meaning of 1 ~ 5 numbers. After reading, counting, speaking and doing various activities, students know the number of 1 ~ 5, and have experienced the formation of the concept of number. Students not only understand the attack and function of number, but also deepen their understanding of the concept of logarithm, and try to look at things around them from a mathematical point of view, gaining a successful understanding and enhancing their determination to learn mathematics well.
Summary of basic knowledge points of senior one mathematics;
★ Summary of compulsory knowledge points in first grade mathematics.
★ Sort out the knowledge points of first-grade mathematics.
★ Summary of difficulties and learning methods of mathematics knowledge points in senior one.
★ Encyclopedia of Mathematics Learning Methods in Different Grades
★ The arrangement of mathematics knowledge points in the first grade of primary school
★ Knowledge points of mathematics in the first grade of primary school
★ Guidance of mathematics learning methods in the first grade of primary school
★ Summary of mathematics learning methods and knowledge points in the first grade of primary school
★ Learn the knowledge points of the first volume of mathematics in senior one.
★ Summary of primary school mathematics knowledge points