TEST_METHOD(CalculationsRoundTests)
{
    int result = Calculations::Round(1.0);
    Assert::AreEqual(1, result);
}

#ifdef EXPORT_TEST_FUNCTIONS
#define MY_CALCULATIONS_EXPORT __declspec(dllexport)
#else
#define MY_CALCULATIONS_EXPORT
#endif
...
class CALCULATIONS_EXPORT Calculations {
...
public:
static int Round(const double& x);

int Calculations::Round(const double& x)
{
    int temp;
    if (floor(x) + 0.5 > x)
        temp = floor(x);
    else
        temp = ceil(x);

    return int(temp);
}