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 RMB" in senior one mathematics.
1. The units of RMB are (yuan), (angle) and (minute).
2. Conversion between RMB units:
1 yuan = 10 angle; 10 angle = 1 yuan; 1 angle = 10 point; 10 point = 1 angle; 10 angle = 100 point; 1 yuan = 100 integral.
3. Main problems:
Fill in the appropriate units. (Pay attention to the actual connection with life)
Calculation: yuan+yuan angle+angle exceeds 10, remember to change it to 1 yuan.
Meta-meta angle-The angle "angle" is not enough to be reduced to "meta" and then calculated by borrowing 1 meta as 10 angle.
4, problem solving: first draw the batch, find the correct data, and then calculate the formula.
The presentation form is "several yuan and several jiao+several yuan and several jiao", not decimal presentation.
5. Change money: 1 block. 10 yuan can get 5 pieces of 2 yuan.
1 block 100 yuan can be exchanged for 5 pieces of 20 yuan. 1, 100 yuan can be exchanged for 2 50 yuan.
1 50 yuan convertible 10 5 yuan.
6, 2.00 yuan =2 yuan; 0.50 yuan =5 cents; 59.90 yuan =59 yuan 9 jiao; 9.25 yuan = 2.5 points for 9 yuan.
The method of mathematics guidance in the first grade of primary school
First, pay attention to the lecture in class and review it in time after class.
The acceptance of new knowledge and the cultivation of mathematical ability are mainly carried out in the classroom, so we should pay special attention to the learning efficiency in the classroom and seek correct learning methods. In class, we should keep up with the teacher's thinking, actively expand our thinking to predict the next steps, and how Billy's own problem-solving thinking is different from what the teacher said. However, due to various reasons, there are often some students who can't keep up with the teacher's ideas and have loopholes in their studies. At this time, on-the-job teachers are needed to give one-on-one counseling to students. In the process of tutoring, the teacher will help students recall what they have learned in one day and guide them to correctly master the reasoning process of various formulas. In a sense, this will help students develop a learning style of asking questions when they don't understand.
In addition, teachers can help students to sort out and summarize one by one at each learning stage, and combine the points, lines and surfaces of knowledge into a knowledge network and bring it into their own knowledge system.
Second, do more questions appropriately and develop good problem-solving habits.
If you want to learn mathematics well, you should do more questions and be familiar with the problem-solving ideas of various questions. At the beginning, we should start with the basic questions, take the exercises in the textbook as the standard, practice repeatedly to lay a good foundation, and then find some extracurricular exercises to fund the development of questions.
How to cultivate children's language ability and how to cultivate children's language ability is also satisfactory. It is a calculation method that directly calculates numbers without using calculation tools, mainly relying on thinking and memory. The new syllabus points out that oral calculation is not only the basis of written calculation, estimation and simplification, but also an important part of calculation ability. It can be seen that to cultivate students' computing ability, we must first start with oral computing ability. So how to cultivate students' oral ability? My experience is that it is very important for teachers to read the three-character classics well: "foundation (grasping the foundation), teaching method (teaching method) and practicing method (routine training)" Reading the word "base" well means basic oral calculation. Oral calculation in primary school mathematics teaching can be divided into three categories: basic oral calculation, general oral calculation and special oral calculation. These three types of oral calculation are mainly based on the content of basic oral calculation, which is the basis of calculation. Basic oral calculation must require proficiency, and proficiency refers to "blurting out", while the other two types of oral calculation only require proficiency or learning. Therefore, we should pay attention to the following aspects:
1. Visual representation of oral calculation
From the form of operation, the oral calculation in the lower grades of primary school is a transition from intuitive perception to imagery operation. For example, establish the appearance of "9+2" in teaching: first show a box with 9 balls, and then prepare 2 balls for students to think. "It depends on a * * *, how many balls are there? How should I put them?" Soon a student said, "I took 1 ball out of the two balls outside the box and put it in the box." There are 10 balls in the box, and there is one outside, a * * *1/." I praised this classmate for speaking well, and explained that this method is called "Ten-complement method", that is, when you see nine, you think of nine, and how many supplements 10. In this way, the appearance is established, and the accuracy of oral calculation has a foundation.
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