Solution:

The mantissa of the final result is 2. According to the principle of multiplication, a unit number is multiplied by a four-digit thousand number 1 ~ ~

The result of multiplying this unit number by four digits must be 2.

There are several situations: the first one is 1×2=2, which is obviously impossible because 1 and 2 have already been used.

The second one is 3×4= 12, you need to try it ~ ~

1 __ __ 4

× 3

——————————

__ __ 5 2

It can be clearly seen that four digits multiplied by three plus 1=5 leaves 6.7.8.9, so it can only be 8.

1 __ 8 4

× 3

——————————

__ __ 5 2

Similarly, the number of 100 digits of four digits multiplied by 3 plus 2=? There are 6.7.9 digits left, and I can't find them.

The next step is to verify this situation.

1 __ __ 3

× 4

——————————

__ __ 5 2

The third is 8×9=72.

The fourth is 4×8=32, and the result can be calculated ~ ~ ~