Can count numbers within 20, can read and write numbers within 20 correctly, and can compare the sizes of these numbers. Can judge the order of numbers within 20 and understand the difference between a few and a few.

Second, the number is less than 20.

Master the number of digits, can judge the composition of numbers within 20, and can explain that every number within 20 is composed of ten and one.

Third, compare sizes.

For example, 1, queue the digital dolls: 5, 6, 10, 3, 20, 17, which can be arranged in descending order or descending order. ? Pay attention to write a number when doing the problem, cross out one, don't be heavy, don't miss it. )

2, take any two numbers within 20, and you can use who is bigger than who or who is stronger than who. For example, 16 is greater than 15, that is, 16 > 15? 9 is less than 13, which means 9 < 13.

3. How to use the word "bi"? Look who is behind the word "Bi". If it is greater than 1, add 1 to the number; if it is less than 1, subtract 1 from the number. ? For example, the number 2 less than 5 is (3), and the number 3 greater than 4 is (7).

Fourth, the calculation method of addition and subtraction within 20

(a) master the calculation method of carry addition within 20.

"Add ten", "Add decimal to divide by large number", add decimal to 10, and then calculate.

For example: 3+9(3+7= 10, 9 can be divided into 7 and 2, 10+2= 12).

"Round up a large number and divide it into decimals", make a large number 10, and then calculate.

For example: 8+7(8+2= 10, 7 can be divided into 2 and 5, 10+5= 15).

Extended data:

7+3= 8+9= 5+5= ? 6+7= 9+ 1= ? 10+ 10= 1 1+9= 6+4=

Answer: 10? 、 17、 10、 13、 10、20、20、 10

References:

Baidu Encyclopedia-Supplement