First look at the unit of the multiplier. What number is multiplied by 6 to get 0?

Either 0 or 5, immediately exclude 0, because if it is 0, then 0 multiplied by 7 equals 0, and there will be no 18XX. So it can be determined that the unit of the multiplier is 5.

The next step is to make sure that the hundredth digit of the multiplicand is 3, which is easy. Multiply more than 300 by 5 to get more than 1800, which conforms to the law, so it is determined to be 376 multiplied by X5.

Look at the ten digits of the multiplier. From bottom to top, the product is greater than 30,000, so in the following four boxes, the thousand digits must be 3.

Let me see. Multiply 376 by 5 to get more than 1800. How many times can I get more than 3000? It should be 8 or 9.

It is further inferred that if it is 9, it will not produce 3 1XX0, and it must be greater than 35000, so the decimal digit of the multiplier is not 9, but 8.

Then, 376*85, the rest is solved.