why does my answer get a lot of decimals

[danzal]

my answer is example 1.000000 why is it so ?

 #include <iostream>
#include <iomanip>
using namespace std;

int main ()
{
	int invno, quantity;
	double up, tp;
	cout << "Please enter the invoice No, Quantity and Unit Price:" ;
	cin >> invno >> quantity >> up ;
	tp = quantity * up;
	cout << left << fixed;
	cout << setw(15) << "Invoice No" << setw(15) << "Quantity" << setw(15) << "Unit Price" << setw(15) << "Total Price"<< endl;
	cout << setw(15) << invno << setw(15) << quantity << setw(15) << up << setw(15) << tp << endl;
		system ("pause");
	return 0;
}
	

.

[JLBorges]

#include <iostream>
#include <iomanip>
using namespace std ;

int main ()
{
    int invno, quantity;
    double unit_price ; //, tp;
    std::cout << "Please enter the invoice No, Quantity and Unit Price:" ;
    std::cin >> invno >> quantity >> unit_price ;

    const double total_price = quantity * unit_price ;

    // http://www.cplusplus.com/reference/iomanip/setprecision/
    cout << left << fixed << setprecision(2) // (fixed) with two digits after the decimal
         << setw(15) << "Invoice No" << setw(15) << "Quantity"
         << setw(15) << "Unit Price" << setw(15) << "Total Price\n"
         << setw(15) << invno << setw(15) << quantity
         << setw(15) << unit_price << setw(15) << total_price << '\n' ;
}