Kindergarten teachers teach children to count from 1 to 20, then slowly to 50, and finally to 100. Counting actually lays the foundation for addition and subtraction.
Children can usually tell the size of a number clearly, but when it comes to numbers before or after a certain number, some children don't know.
Therefore, children should be taught to distinguish between the numbers before and after each number. For example, 5 is preceded by 4 and followed by 6, so that children can know how to count backwards and forwards.
Like 8+7=? Remember 8, counting from 7, 9, 10,1,12, 13, 15, you will know that the number is 15.
8-3=? Remember 8, count forward 3, 7, 6, 5, and you will know that the number is 5.
2. Proficiently recite the division and combination of numbers within 10, and skillfully use the "ten methods" and "ten methods".
By taking advantage of children's good memory and skillfully reciting the division and combination of numbers within 10, they can skillfully calculate the addition and subtraction of numbers within 10.
Memorizing the division and combination of 10 laid the foundation for the method of adding ten and the method of breaking ten.
For example, 8 can be divided into 1 and 7, 2 and 6, 3 and 5, 4 and 4, 5 and 3, 6 and 2, 7 and 1, so when you see 3+5, you immediately think of 8.
10 can be divided into 1 and 9,2 and 8,3 and 7,4 and 6,5 and 5,6 and 4,7 and 3,8 and 2,9 and 1.
"Add up to ten" (addition) is to look at large numbers, divide them into decimals, add up to ten, and add up the remainder; Decimal method (subtraction) is to divide a large number by 10 and a few, then subtract the following numbers with 10, and finally add the remainder.
Like 9+7=? Divide 7 into 1 and 6,9 and 1 do 10, and add the remaining 6 to make 16.
17-8=? Divide 17 into 7 and 10, then subtract 8 from 10 to get 2, and finally add 2 to 7 to get 9. (as shown in the figure below)
In short, preschool children first teach them easy-to-understand and easy-to-remember addition and subtraction, laying the foundation for grade one. If it is too complicated, it will discourage children from learning mathematics. The above two methods are recommended. The first method is relatively simple, and the second method is not difficult for children to learn as long as they memorize the division and combination of 10.