Different ways of passing values to function

FunctionValuePass.ccp

/*Passing Results of one function to another function
It is easy... Damn, I dont i Tinker with my code more often
I only realised this after doing Python course on Codecadmy 
*/
#include <iostream>

using namespace std;

int add_Number(int a , int b)
{
    return a+b;
}
int multiply(int a , int b)
{
    return add_Number(a,b)*a*b;//This works like python
}

int main(void)
{
    int a = 0 , b =0 ,c =0;
    cin>>a>>b>>c;
    cout<<add_Number(a,b)<<endl;
    cout<<multiply(a,b)<<endl;
    cout<<multiply(add_Number(a,b),c)<<endl;//Why the hell did i never try it before

    return 0;
}