for ( int A = 10; A <= 31; A++)
        {
            for ( int B = 10; B <= 31; B++)
            {
                for ( int C = 10; C <= 31; C++)
                {

                    for ( int D = 10; D <= 31; D++)
                    {

                        while (A == 31)
                        {
                          Fdiv = A/B * C/D
                     //Code to fill all 5 values in
                    // DataTable "Changeable", automatic

                        }
                      }
                 }
            }
          }