Good friends1919,2828, hand in hand, 3737 is really close, and 4646 will go together. Make a pair of hands in half.

Namely:1+9 =10; 2+8= 10; 3+7= 10; 4+6= 10; 5+5= 10

meaning

A method of decomposing an addend into two numbers, so that one part of the decomposed addend is added with another addend to get 10, and then the other part is added with 10, which is the method of filling ten. Its basic principle is to make the sum of two numbers 10, and then become 10 plus a few calculation methods.

skill

For example: 9+2= (), according to the ten-point method: 9 and 1 add up to 10, that is, 9+ 1= 10, and the following "2" separates "65430". Others and so on, such as:

How can I quickly master the ten-point method?

The main thing is to remember the numbers and laws that can make up ten, such as "9 to 1", "8 to 2", "7 to 3", "6 to 4" and "5 to 5".

The general method is:

1, take a look. what are you reading? Looking at a big number means looking at a bigger number in the formula.

2. Dismantle. Refers to the decimal, that is, the smaller number in the middle.

3. Form ten. That is, divide the smaller one by a number and add it to the larger one to get ten. For example, 8+6 can divide 6 by 2 and 4.

4. Jia Lian. 8+6 After dividing 6 into 2 and 4, use 8+2+4.

Summary:

Ten-complement method is the basic method of carry addition within 20, which is based on the knowledge points of 10 plus a few that children have learned before. By using the method of filling ten, the carry addition within 20 can be transformed into the problem of adding several words to 10, which is familiar to children, and it embodies the transformation idea in mathematics, thus making it difficult and easy. It can not only improve the accuracy of calculation, but also effectively improve the speed of calculation, which is of great help to children's later learning.