#include <iostream>
using namespace std;

double Abs(double Nbr)
{
	if( Nbr >= 0 )
		return Nbr;
	else
		return -Nbr;
}

double SquareRoot(double Nbr)
{
	double Number = Nbr / 2;
	const double Tolerance = 1.0e-7;

	do Number = (Number + Nbr / Number) / 2;
	while( Abs(Number * Number - Nbr) > Tolerance);

	return Number;
}

int main()
{
	double Number = 1448.64;
	double Nbr    = SquareRoot(Number);

	cout << "The square root of " << Number << " is " << Nbr << "\n\n";

	return 0;
}

Here is an example of running the program:

The square root of 1448 is 38.0526
Press any key to continue