How to teach the first grade of primary school over 10 plus plus minus

Lian Plus:

Consecutive minus:

The Law of Addition:Addition has several important properties. It is commutative, which means that the order is not important, it is again interrelated, which means that when more than two numbers are added, the order in which the addition is performed does not matter, the repeated addition of 1 is the same as the count, the addition of 0 does not change the result, and the addition also follows related operations (such as subtraction and multiplication).

Addition is one of the simplest numerical tasks, the most basic addition: 1+1, which can be calculated by a five-month-old baby, or even other animal species, and in primary education, students are taught to perform superposition calculations of numbers in the decimal system, starting with a digit of one digit and gradually solving more difficult numerical calculations.

For first-grade students within 10 years of addition and subtraction still can't do, indeed, first-grade children should not be difficult for such problems, but children still can't do it, maybe there are some problems. I hope that parents will analyze the reasons and identify the problems, so that parents know how to educate.

First of all, I think you have to see if the child has reached the age of school, because the child's intelligence is related to age, if the age is not enough, you can consider letting the child go to the corresponding educational institution, otherwise blindly let the child pursue too high learning goals, will undoubtedly increase the burden of the child, is not good for the child's mental health and physical development, is tantamount to pulling out the seedlings to help grow!

Secondly, if the child meets the admission requirements, as a parent, you should build self-confidence, be patient enough, encourage your child more, take your child to do more games about mathematics and science, develop intelligence, and believe that after a period of hard work! There will be a satisfying result!

Moreover, parents must not reprimand or ridicule their children, do not compare their children with other children, and do not give their children a feeling of "stupidity", because your child is now a potential student, once the child's potential is stimulated, maybe he will be a mathematician in the future!

The general reason is that the concept of numbers is not clear, and it is necessary to use objects in life, such as fingers, small sticks, abacus, etc., to introduce children to the correspondence with numbers. Then teach the decomposition and composition, and finally transition to addition and subtraction.

Even plus and minus in the first grade. "Addition and subtraction" is selected from the fifth unit of the first grade mathematics volume, this unit teaches addition and subtraction within 10, and the knowledge point of addition and subtraction is often used to solve the problems we encounter in daily life, and it is placed behind the addition and subtraction of two numbers within 10, on the one hand, it is an expansion of the meaning of addition and subtraction, and on the other hand, it also reflects the concept of the new curriculum standard that everyone can obtain the necessary mathematics.

Introduction

This is also a difficult content of this unit, the main difficulty is in the calculation process, it is necessary to carry out oral arithmetic in two steps to calculate the result, especially the second step of calculation to use the number calculated in the first step as an addition or subtraction, in order to complete the calculation task. And this way of thinking is very helpful for learning to carry addition within 20.

Example 12 is to teach the pumpkin diagram to add up, it is recommended to let the students talk about what they see on the map, what kind of mathematical problems can be raised, and how to solve the column after the proposal The students will definitely have a variety of answers, the teacher collects and summarizes various answers, and then asks the students to communicate, say the meaning of their own column of calculations, and finally summarizes the calculation formula of continuous addition: 4+2+1=9, in order to let all students accept the continuous addition formula, students should be asked to talk more about the meaning of each number in the formula, The meaning of the whole equation and so on, and the teaching of subtraction example problems is roughly the same process.

The questions of addition and subtraction within 10 are as follows:

10 can be divided into 1 and 9

10 can be divided into 2 and 8

10 can be divided into 3 and 7

10 can be divided into 4 and 6

10 can be divided into 5 and 5

In Grade 1 Mathematics, the "Ten Method" is a commonly used method of carrying and adding, such as 7+5 (7+3)+2 or (5+5)+2;

The "continuous subtraction method" should be a method of abdication and subtraction, that is, the subtraction is divided into two subtractions, first removing the "fraction" of the subtracted number, and then subtracting the difference between the "fraction" and the subtraction, for example; 15-8＝15-5-3；

In addition, there is the "Ten Ways to Break."

Break the ten laws, borrow the ten laws, and level the ten laws.

The method of breaking ten is to first divide a 10 from the subtracted number and then subtract the subtraction from 10, and the resulting difference is added to the remaining number of the subtracted number to obtain the result.

The use of "borrowing 10 methods" can transform subtraction into problems that students are familiar with 10 minus a few points, so as to simplify the difficulty. When the single digit is not enough to subtract, subtract the subtraction with 10 and add the remaining number.

The "flat ten method" is that when the single digit of the subtracted number is not enough to subtract, the subtraction is divided into two numbers, and the subtracted number should be equal to 10 after subtracting the first number, and then subtracting the second number with 10 to get the final result.

Grade 1 Mathematics, Ten Methods, Continuous Subtraction, and what other methods are most commonly used in Grade 1 Mathematics "Ten Methods", such as 7+5=(7+3)+2 or =(5+5)+2;"Continuous subtraction" should be a method of abdication, that is, the subtraction is divided into two subtractions, first removing the "zero" in the subtraction, and then subtracting the difference between the "zero" and the subtraction; 15-8=15-5-3；There is also a "ten-point method" that first subtracts the subtraction 10 (10 points) and then adds the "zero" of the subtraction, e.g. 15-8 = 10-8 + 5. FYI.

In the first grade, rounding is a common method of adding bearings, for example, 7+5=(7+3)+2 or =(5+5)+2;"Continuous subtraction" should be a way to abandon subtraction, i.e. subtraction is divided into two subtractions, first removing the "odd" of the subtraction, and then subtracting the difference between the "odd" and subtraction, for example; 15-8＝15-5-3；In addition, there is the "decimal method", which is to subtract (decimal fold) from 10 and then add the "odd part" of the negative number, e.g. 15-8 = 10-8 + 5.

In first-level mathematics, rounding is a common method of carrying addiction, such as 7+5=(7+3)+2 or =(5+5)+2;"Continuous subtraction" should be a subtraction renunciation method, i.e. subtraction is divided into two subtractions, first removing the "odd" of the subtraction, and then subtracting the difference between the "odd" and the subtraction, for example; 15-8＝15-5-3；There is also the "tenth" method, which is to subtract the subtraction (10 points) from 10 and then add the "odd part" of the negative number, e.g. 15-8 = 10-8 + 5.

The first type of mathematics, compact -10, and even subtraction, and the first type of mathematics "compact -10" are general carry methods, such as 7+5=(7+3)+2 or =(5+5+2); "Continuous subtraction" should be a deviation from subtraction.

2. A method of subtracting the "zero" part of the norm from subtraction, for example; 15-8=15-5-3；In addition, "ten violations", that is, "ten violations", that is, "ten violations" means "ten violations". The first is 10-minus minus (10 disconsecutive) plus "zero" minus minus, e.g. 15-8 = 10-8+5. FYI.

In first-grade math, rounding is a common method of carry addition, such as 7+5=(7+3)+2 or =(5+5)+2;"Continuous subtraction" should be a way to abandon subtraction, i.e. subtraction is divided into two subtractions, first removing the "odd" of the subtracted number, and then subtracting the difference between the "odd number" and the subtraction, for example; 15-8＝15-5-3；In addition, there is the "tenths", where the subtraction (tenths) is subtracted from 10 and the "odd part" of the subtracted is added, for example, 15-8 = 10-8 + 5. FYI.

There are also ten ways to break, ten ways to borrow, and ten ways to level.

Side loss 1, carry addition calculation method.

Whether it is a two-digit plus a one-digit number, a two-digit plus a two-digit number is applicable, the most basic principle and potato are the addition principle within 20, and the quick calculation formula for carry addition within 20 is: several + 9, advance 1 minus 1; a few +8, 1 minus 2; a few + 7, into 1 minus 3; a few +6, 1 minus 4; a few + 5, into 1 minus 5; The invoker is a few +4, 1 minus 6; a few + 3, into 1 minus 7; a few + 2, 1 minus 8; A few + 1, 1 minus 9.

2. The short-answer calculation method of abdication subtraction.

The abdication subtraction of the number within 100 is also based on the abdication subtraction of the number within 20, and the quick calculation formula of the abdication subtraction is: several -9, ten + 1 retreat;Few-8, 10+2;Few-7, 10+3;Few-6, 10+4;Few-5, ten + 5;Few-4, 10 + 6;Few-3, 10+7;Few-2, 10+8;A few -1, ten + 9. Since the subtraction and the subtraction cannot be exchanged, in subtraction, the two single digits are observed first, and when the subtraction is larger than the single digit of the subtracted number, the answer can be quickly calculated according to the subtraction formula.