Addition is actually adding two sets together to become one set.
Subtraction: Divide a set into two parts.
Children really understand the meaning of addition and subtraction, not knowing the problem, but understanding the relationship between addition and subtraction. For example, six apples can be divided into two and four apples and vice versa. Meanwhile, two and four apples (or four apples and two apples) add up to six apples. That is to say:
1, teach children from the beginning of decomposition and combination. While expressing it in words, you must say it with your mouth. The child who can say it shows that she has really mastered it.
It starts in 2.5 minutes. Let's talk about decomposition 2 first.
Remember to put them together after each separation.
I hope I can help you.
* * * * The method of laying the foundation 1, learning to count.
Everyone knows that you should learn to count before you learn to calculate, but using various counting forms to lay the foundation for calculation has been ignored by quite a few parents. Many parents think that their children can learn to count by singing and reading 1 ~ 100, and they can teach calculation, but in fact, their children have not really established the concept of counting and mastered the skills of counting.
In fact, there are many contents of counting. In addition to establishing the concept of one-to-one counting, it also includes a variety of counting techniques. The main forms are:
①N plus 1, that is, counting in the order of 1 increasing, which is the basis of learning N plus 1;
②N minus 1, that is, counting down in descending order of 1, which is the basis of learning N minus 1;
③ Odd number, establishing the concept of odd number;
④ Counting even numbers and establishing the concept of even numbers;
⑤ When the number is 10, establish the concept of carry;
⑥ Taking 5 as the basic unit is a very important counting skill, because 5 is second only to 10 in improving counting and calculation skills.
2. Calculate n plus 1. Any child who can count in turn and understand that it means to increase 1 can easily learn to calculate n plus 1, including 10 plus 1, 20 plus 1, 99 plus 1, and even 65438.
3. Calculate N minus 1. Any child who can count backwards and understand the meaning of minus 1 can learn to calculate N minus 1, including 1 1 minus 1, 2 1 minus 1 and/kloc-0.
4. Addition and subtraction of integer 10, such as 10 plus 10, 20 plus 10, ... 90 plus 10. Children who can count every 10 and understand its meaning are eager to learn.
5. Addition and subtraction of whole five, such as 0 plus 5, 5 plus 5, 10 plus 5, or even 95 plus 5, is not difficult for children who can count every five and understand that it means addition and subtraction.
6. Calculate 10 plus n, including 10 plus 1, 10 plus 2... 10 plus 9. Once children understand that 10 plus a few equals more than ten, they can not only quickly calculate 10 plus n, but also generalize it to 20 plus n.
7. Add two identical numbers, including 1 plus 1, 2 plus 2 ... nine plus nine. For children who can count even numbers, when they find that the result of adding two identical numbers is even, they will easily learn to calculate such problems. Teaching practice shows that children generally have spontaneous concern and interest in two problems of adding the same number, so children often have to master this group of problems before non-N addition 10.