怎么回事啊，求助

public class HelloWorld{
public static void main(String[] args){
int num = 999;
int count = 0;
if (num>0&&num<=999999999)
 {   while(num!=0)
    { count++;num/10;}
    System.out.println("它是个"+count+"位的数!");
 }
else
 { System.out.println("cuowu");
 }

}
}

//它说error: not a statement

    { count++;num/10;}

                 ^

1 error怎么回事啊