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 ~ ~ ~