C++ Code sum and multiplication by using class oboject

#include <iostream>
#include <math.h>
using namespace std;
class summation
{
     int a,b,sum,mul;
public:
    void getdata();
    void calculation();
    void putdata();

};
void summation ::getdata()
{

    cout<<"enter two numbers: ";
    cin>>a>>b;
}
void summation ::calculation()
{

    sum=a+b;
    mul=a*b;
}
void summation ::putdata()
{
    cout<<sum<<" "<<mul;
}
int main()
{

    summation s;
    s.getdata();
    s.calculation();
    s.putdata();
}