why addition of pointer is not possible

why addition of pointer is not possible

Pointer are actually a variable with 2bytes of memories and it stores the address of any another variable ..so value stored in pointer will be the address and not the value of that variable..

for example:

suppose
int a =5;
int *p=&a;

and address of a is 115 and tht of p is 225...
now the above code states tht

value of a = 5;
value of p = 115;//address of a