A website about the quadratic formula by completing the square (CTS). Completing the square is the fourth step to the quadratic formula. We will take you step by step on how to complete the square for every problem scenario. If you would like to work on some problems click here. If you would like step-by-step explained examples click here. A prezi presentation is also available here. If you would like video demonstration on how to complete the square click here. If you would like to play games on completing the square click here. And if you would like to see a list of careers that include completing the square click here.