c++: Kaprekar number test loop (list all Kaprekar numbers under 10,000)

This is what I have so far, I can't seem to figure out where it isn't working at...

#include

using namespace std;

int main(){

//declare variables

int num, squaredNum, firstHalf, secondHalf, unit, test;

//initialize number

num = 1;

//while loop

while(num < 10,000){

squaredNum = num * num;

if (squaredNum < 100){

unit = 10;

}

else if (squaredNum < 1000){

unit = 100;

}

else if (squaredNum < 10000){

unit = 1000;

}

else if (squaredNum < 100000){

unit = 10000;

}

firstHalf = squaredNum/unit;

secondHalf = squaredNum%unit;

test = firstHalf + secondHalf;

if (test == num){

cout << num << " is a kaprekar number!" << endl;

num++; //increment number

}else {

num++; //increment & continue to next number

}

}//end while loop

return 0;

}