余数除法和不允许除以零 (c++） 时遇到问题

嗨，我对 c++ 和堆栈溢出相对较新。如果在提问时有任何特定的协议，请非常诚实，这样我在问其他问题时就不会犯同样的错误。

我正在尝试创建一个程序，该程序采用下图所示的输入。我想让用户不能除以零。我还想在计算后有十进制输出，但程序四舍五入到下。例如，如果我说股票股价是 50 1/2 并且有 10 个，那么它显示 500 而不是 505。

提前感谢！

#include <stdio.h>
#define addr(var) & var // programmer defined macro definition 
#define MAXINT 2^32-1
int main(void)
{
char Ticker[6+1]; //Declare Ticker as String
int numOfShares;
float whole,num,dem;
float pricePerShare;
float stockValue; 
int i=0;
bool inputOK = false;
int value;



for (i=1; i <= 10; i++)
{

printf("Enter the stock Ticker ==> ");
scanf("%s",&Ticker[0]);         //Accept Ticker
printf("How many shares of %s were purchased: ",Ticker);
scanf("%d",&numOfShares);
printf("What is the price per share: ");
scanf("%d %d/%d",addr(whole), addr(num), addr(dem));

pricePerShare = whole + num / dem;
stockValue = numOfShares * pricePerShare;

printf("            Ticker  Number of   Price Stockn");
printf("            Symbol  Share       Per Share  Valuen");
printf("            =====   ==========  =========  ======n");
printf("%6s     %4d         %7.2f       %8.2fn",
Ticker, numOfShares,pricePerShare,stockValue);
// %7.2f --> 9999.99
}
printf(" Press any key to continue ...");

fflush(stdin);
getchar();
return 0;

}