1, complete the array method.

The complete array method is a classic method of supplementing ten, and it is a method of supplementing ten by adding and subtracting numbers. For example, the numbers 7+3 = 10 and 7-2 = 5, which is a complete array method.

2. Composite method.

The combined number method is to divide a number into two numbers and then combine them to make their sum equal to 10, for example, 5+5= 10 and 8+2= 10, which is the combined number method.

3. Split number method.

The factorization method is a method to decompose a number into the sum of several numbers so that their sum is equal to 10. For example, 7+2+ 1= 10, 6+3+ 1= 10, which is a divisor method.

Brief introduction of ten-point method

Ten times ten is a carry addition within 20. Firstly, an addend is divided into two numbers, so that the decomposed one and the other addend form 10, and then they are added to the decomposed other number. This calculation method is called ten times ten method.

Ten-point formula

Look at the big numbers, divide them into small numbers, make ten, and add the rest. Clap your hands and nod, children. Let's sing ten songs. One plus nine, ten little frogs; Two plus eight, ten old ducks; Three plus seven, ten old chickens; Four plus six, ten macaques; Five plus five, ten big tigers.

Ten-point method

Oral arithmetic is a very important ability for primary school students. The improvement of children's oral calculation speed can save some learning time, improve learning efficiency, improve children's interest in learning mathematics, and help children build or enhance their confidence in learning mathematics well.

In the mathematics teaching of grade one or two in primary schools, the method of "adding up to ten" is often used to calculate the addition and subtraction within 20. Ten is a crutch. 10 can be decomposed into several and several, and several and several can make up 10. As long as you master the decomposition and composition of 10 quickly and accurately, you will be able to calculate the addition and subtraction within 20 correctly and quickly.