Do...While Correction Needed

I just recently started learning this stuff so I am sure I am doing something simple but I don't really notice a difference from my book examples. I am trying to have the program loop back to ask the original question "Enter and operation: + - * / (or enter X to exit): " but instead it loops through the if statement. So it keeps asking me for a number instead of a new operator and THEN a new number, but it's not actually performing the math either. This program is supposed to continuously perform math to a number until you press "X" to stop.

Code:

`do `

{

cout << "Enter and operation: + - * / (or enter X to exit): "; cin >> oper;

if (oper = '+')

{

cout << "Enter a number: "; cin >> num;

tot = tot + num;

cout << "Current total is " << tot << endl;

}

if (oper = '-')

{

cout << "Enter a number: "; cin >> num;

tot = tot - num;

cout << "Current total is " << tot << endl;

}

if (oper = '*')

{

cout << "Enter a number: "; cin >> num;

tot = tot * num;

cout << "Current total is " << tot << endl;

}

if (oper = '/')

{

cout << "Enter a number: "; cin >> num;

tot = tot / num;

cout << "Current total is " << tot << endl;

}

else cout << "Enter a valid number." << endl;

}

while (oper != 'X' || oper != 'x');