13,because it’s the single number that divides with 52
52:13=4
How much after subtraction
4 x 2/4
2/4 can be reduced to 1/2
Now you have 4 x 1/2
Multiply 4 by 1 then divide by 2:
4 x 1 = 4
4/2 = 2
The answer is 2
If the answer can be left in a fraction than this is the solution: 2×5/8=5/4
5/4-1/3=11/12
if you mean the answer must be left in a whole number than.. I don't really know how to do it
For this case we propose a rule of three:
31700 ------------> 8.8%
x ----------------------> 100%
Where "x" represents the number of copies sold to date.

Thus, to date 360,227 copies of the book have been sold.
ANswer:
To date, 360,227 copies of the book have been sold.