Code
#include "stdafx.h"
#include <iostream>
int main();

void DecToBin(int y)
{
using namespace std;
for(int x = 256; x /= 2;)
if(y >= x)
(cout << "1") && (y -= x);
else
cout << "0";
cout << "nn";
main();
}

int main()
{
using namespace std;
cout << "enter a number: ";
int y;
cin >> y;
DecToBin(y);
return 0;
}

(To use windows calculator in this manner, go to the View menu and choose “scientific” — then you can access the Dec and Bin buttons, which are decimal and binary).

The wordpress spam filter does a really good job of catching stuff, but it occasionally gets false positives. I restored the version of your article that it marked as spam and told it that it wasn’t spam. It’s supposed to learn from past behavior, so hopefully next time it will be smarter about how to treat wikihow links.

But I prefer this method for decimal to binary conversion::
Short division by two with remainder

This method is much easier to understand when visualized on paper. It relies only on division by two.

1. For this example, let’s convert the decimal number 156 to binary. Write the decimal number as the dividend inside an upside-down “long division” symbol. Write the base of the destination system (in our case, “2″ for binary) as the divisor outside the curve of the division symbol.

2)156
2. Write the integer answer (quotient) under the long division symbol, and write the reminader (0 or 1) to the right of the dividend.

2)156 0
78
3. Continue downwards, dividing each new quotient by two and writing the remainders to the right of each dividend. Stop when the quotient is 1.

2)156 0
2)78 0
2)39 1
2)19 1
2)9 1
2)4 0
2)2 0
1
4. Starting with the bottom 1, read the sequence of 1’s and 0’s upwards to the top. You should have 10011100. This is the binary equivalent of the decimal number 156.

source:
http://www.wikihow.com/Convert-from-Decimal-to-Binary

[ It should have been converting -76 to binary. Fixed! -Alex ]

[ Try the lesson on bitwise operators. -Alex ]