4- Span is the horizontal line with index number 4, and under 18- is the vertical line with index number 18.
According to the conditions given in the title, vertical lines 2, 4, horizontal line 27 and vertical line 27 all have numbers, so start with these four numbers.
Look at the vertical line 2 first, the number is 82, and the clue is 2 times 2 1- span (twice that of the horizontal line 2 1).
Then the number of 2 1 is 4 1.
Look at the vertical line 4, the number is 3 1, and the clue is to see 8- span. Then look at the clue box of 4-down (the box of vertical line 4).
Then the number in line 8 is 96 1.
And so on.
Send you the answer:
3 8 4 4 X 3 3 6 2
2 2 X 9 6 1 X 4 0
8 X X X 7 X X X
2 7 X 1 8 2 X 1 5
X 7 0 2 X 3 5 1 X
1 9 X 2 2 5 X 4 1
6 X X X 2 X X X 1
4 5 X 1 6 9 X 1 3
1 6 8 1 X 1 4 0 0
(where x represents the black box in the title)
It took me a long time to do it. I hope you can adopt it. You can ask if you don't understand.