Below is a basic Calculator i made using Inline ASM in C++. The functions include addition, subtraction, division and multiplication.

Code:
/*
Basic Asm Calculator
Showing how to code some simple functions
in C++ using Inline Asm!

Just on the Asm Functions you do not need
to have the ';' at the end of each line
I have just come custom to it but it make no
great deal!
*/

#include <windows.h>
#include <iostream.h>

//Function Prototypes need to be declared the 'main'
//function however does not need to be declared
int Add(int x, int y);
int Sub(int x, int y);
int Div(int x, int y);
int Mul(int x, int y);


int main ()
{
	int func;          //Function to use, see the switch statement
	int x,y;           //x and y = number 1 and number 2 respectively :)
	bool finish=false; //just a boolean so the program won't close ;)

	while (finish==false) //loop begins so program won't exit when done :D
	{
		cout<<"1:Add, 2:Sub, 3:Div, 4:Mul\n";
		cout<<"Please enter a number to represent the function\n";
		cin>>func; //enter number representing the proper function
		cout<<"Enter first number\n";
		cin>>x; //enter first number 
		cout<<"Enter second number\n";
		cin>>y; //enter second number

		switch(func) //remeber func is an integer type
		{
		case 1:
			cout<<Add(x,y)<<endl; //if func = 1 then Add x and y
			break;
		case 2:
			cout<<Sub(x,y)<<endl; //if func = 2 then subtract x and y
			break;
		case 3:
			cout<<Div(x,y)<<endl; //if func = 3 then divide x and y
			break;
		case 4:
			cout<<Mul(x,y)<<endl; //if func = 4 then multiply x and y
			break;
		}
	}
	return 0;
}


int Add(int x, int y)
{
	__asm
	{
		mov eax,x;
		mov ebx,y;
		add eax,ebx;
		mov x,eax;
	}
	return x;
}

int Sub(int x, int y)
{
	__asm
	{
		mov eax,x;
		mov ebx,y;
		sub eax,ebx;
		mov x,eax;
	}
	return x;
}


int Div(int x, int y)
{
        __asm
        {
        mov eax,x;
        mov ecx,y;
        sub edx,edx;
        div ecx;
        mov x,eax;
        }
        return x;
}

int Mul(int x, int y)
{
	__asm
	{
        mov eax,x;
        mov ebx,y;
        mul ebx;
        mov x,eax;
	}
	return x;
}
Hope it helps a little