Калькулятор выдает неправильный результат

#include <iostream>
 
using namespace std;
 
double summ(double* first_num, double* second_num)
{
    return *first_num + *second_num;
}
double subtraction(double *first_num, double *second_num)
{
    return *first_num - *second_num;
}
double multip(double *first_num, double *second_num)
{
    return *first_num * *second_num;
}
double division(double *first_num, double *second_num)
{
    return *first_num / *second_num;
}
 
 
void main()
{
 
    {
        int tmp = 0;
        double frist_num = 0;
        double second_num = 0;
        double result = 0;
 
        cout << "enter first number -> ";
        cin >> frist_num;
        cout << "\n";
 
        double(*sum1)(double*, double*) = summ;
        double (*subtraction1)(double*, double*) = subtraction;
        double (*multip1)(double*, double*) = multip;
        double (*division1)(double*, double*) = division;
 
        void* operation[4]{ *sum1, *subtraction1, *multip1, *division1 };
        cout << "[1] sum (+)\n" << "[2] subtraction (-)\n" << "[3] multip (*)\n" << "[4] division (/)\n";
        cout << "Select an action -> ";
        cin >> tmp;
        cout << "\n";
 
        cout << "enter second number -> ";
        cin >> second_num;
        cout << "\n";
 
        result = *(double*)operation[tmp];
        cout << "result -> " << &result << "\n";
    }
}

typedef double (*operation_t)(double *, double *);
operation_t operation[4] = { summ, substraction, multip, division };
// ...
double result = operation[tmp](&first_num, &second_num);

#include <iostream>
 
using namespace std;
 
 
double summ(double* first_num, double* second_num)
{
    return *first_num + *second_num;
}
double subtraction(double *first_num, double *second_num)
{
    return *first_num - *second_num;
}
double multip(double *first_num, double *second_num)
{
    return *first_num * *second_num;
}
double division(double *first_num, double *second_num)
{
    return *first_num / *second_num;
}
 
 
void main()
 
    {
        int tmp = 0;
        double frist_num = 0;
        double second_num = 0;
 
        cout << "enter first number -> ";
        cin >> frist_num;
        cout << "\n";
 
        typedef double (*operation_t)(double*, double*);
        operation_t operation[4] = { summ, subtraction, multip, division };
        cout << "[1] sum (+)\n" << "[2] subtraction (-)\n" << "[3] multip (*)\n" << "[4] division (/)\n";
        cout << "Select an action -> ";
        cin >> tmp;
        cout << "\n";
 
        cout << "enter second number -> ";
        cin >> second_num;
        cout << "\n";
 
        double result = operation[tmp](&first_num, &second_num);
        cout << "result -> " << result << "\n";
    }
}