According to the meaning of the question, there are no duplicate numbers in each row and column.

∴ Start from the upper left corner of the box.

There are three ways to fill in this form.

There are two results in the grid on the right, and the number in the third grid on the right is a number after the first two numbers are determined.

Find a routine method:

1, serial number: to find a regular topic, a series of quantities arranged in a certain order are usually given, and we are required to find a general rule according to these known quantities. Find out the rule, usually the serial number of the package. Therefore, it is easier to find the mystery by comparing variables with serial numbers.

2. Fibonacci sequence method: each number is the sum of the first two numbers.

3. Arithmetic series method: the difference between every two numbers is equal.

4. Tabbing method: You can look at it every once in a while to see what the relationship between the separated numbers is, for example, 14, 1, 12, 3, 10, 5, odd items become arithmetic progression, even items also become arithmetic progression, and then you have to fill in 8.