Stack Postfix Calculator

Can anybody tell me what's wrong with this? I get an answer but its wrong. For example 23+ gives me 225.

Code:

#include <iostream>
#include <iomanip>
using namespace std;
 
class node
{
  public:
    float number;
    node *next;
};
 
node* push(node *stack, float data)
{
  node *utility;
  utility = new node;
  utility -> number = data;
  utility -> next = stack;
  return utility;
}
 
node* pop(node *stack, float &data)
{
  node *temp;
  if (stack != NULL)
  {
    temp = stack;
    data = stack -> number;
    stack = stack -> next;
    delete temp;
  }
  else cout << "\nERROR: Empty stack.\n";
  return stack;
}
 
int main()
{
  float answer, operand1, operand2;
  char ch = ' ';                                    
  node *utility, *top;
 
  utility = new node;
  utility -> number = 0;
  utility -> next = NULL;
  top = new node;
  top -> number = 0;
  top -> next = utility;


  while(ch != 'q')
  { 
 cout << "calc> ";
 cin >> noskipws >> ch;
	if(ch == 'q')
	{
		return 0;
	}
 while(ch != '\n')
 {
	  
        
        float operand = 0;
        if((ch >= '0')&&(ch <= '9'))
		{
          while(ch != '\n')
		  {
            operand = operand*10 + (ch-48);
			  
            cin >> ch;
		  }
          top = push(top, operand);
		}
        else
		{
			if((ch == '+')||(ch == '-')||(ch == '*')||(ch == '/')){
          top = pop(top, operand1);
          top = pop(top, operand2);
          switch(ch){
            case '+': answer = operand2 + operand1;
				break;
            case '-': answer = operand2 - operand1;
				break;
            case '*': answer = operand2 * operand1;
				break;
            case '/': answer = operand2 / operand1;
				break;
		  }
		  top = push(top, answer);}
			else {
				cout << "Error! Wrong Character Entered";
			}
		}
		pop(top, answer);
  cout << "\nAnswer: " << answer << endl;
  
}
  }
}

Please don't repost..
Stack Postfix Calculator