//**********************************************
// Online C++ Compiler.
// https://www.onlinegdb.com/online_c++_compiler
//**********************************************

#include
#include       /* round */

using namespace std;

int main()
{
    unsigned int MagicNumber, RolledNumber;
    double dTemp;
    
    MagicNumber = 4294752547;
    
    printf("\n Rounding Decimals to the Nearest Whole Number.");
    
    // #0
    dTemp = (double) (MagicNumber - 1) / 429496.7295;
    RolledNumber = (unsigned int)round(dTemp);
    printf("\n MagicNumber - 1 = %lu, dTemp = %.08f, RolledNumber = %lu.", MagicNumber - 1, dTemp, RolledNumber);
    
    // #1 (success)
    dTemp = (double) MagicNumber / 429496.7295;
    RolledNumber = (unsigned int)round(dTemp);
    printf("\n MagicNumber = %lu, dTemp = %.08f, RolledNumber = %lu.", MagicNumber, dTemp, RolledNumber);
    
    // 2^32 = 4294967295 + 1, 4294967295 - 4294752547 + 1 = 214749.
    printf("\n Conclusion. There are only 214749 numbers for which a rolled number will be 10000.");
    printf("\n The first suitable number is %lu.", MagicNumber);
    printf("\n WIN CHANCE is %.06f %% per each roll.", 214749.0/4294967296.0 * 100.0);

    return 0;
}  

Output:
 Rounding Decimals to the Nearest Whole Number.
 MagicNumber - 1 = 4294752546, dTemp = 9999.49999852, RolledNumber = 9999.
 MagicNumber = 4294752547, dTemp = 9999.50000085, RolledNumber = 10000.
 Conclusion. There are only 214749 numbers for which a rolled number will be 10000.
 The first suitable number is 4294752547.
 WIN CHANCE is 0.005000 % per each roll.