Answer
$\ 12! = 479,001,600$
Stirling's Formula:
$\ 12! = 475,687,487$
Work Step by Step
$$\ 12! = 12 \times 11 \times 10 \times 9 \times 8 \times 7 \times 6 \times 5 \times 4 \times 3 \times 2 \times 1$$
$$\ 12! = 479,001,600$$
$\ Stirling's$ $Formula:$
$$\ 12! \approx \left(\frac{12}{e}\right)^{12} \sqrt{2\pi(12)} \approx 475,687,487$$