1. integer addition calculation rules:

The same numbers are aligned from the low order. When the numbers add up to ten, they will advance to the previous number.

2. The integer subtraction calculation rules:

The same numbers are aligned. If the number of digits is not reduced enough, it will be reduced from the previous digit and merged with the number in the standard.

Multiplication:

(1) How much is it?

(2) How many times is a number;

③ Find the area and volume of the object;

(4) Find the fraction or percentage of a number.

Department:

(1) divide a number into several parts on average and find one of them;

(2) How many other numbers are there in a number;

(3) What fraction or percentage of a number is known to find this number;

(4) Find a number that is several times that of another number.