How can I be more accurately using the Vector 3?

X, y and z I have six decimal places. When I use the MoveTowards method I create a Vector3 and step values of x, y and z. At that moment Vector3 rounds six decimal places to one. The values of x, y and z is the initial position of a GameObject before moving forward, when do GameObject back to the starting position I lose the accuracy of decimal places and the GameObject is crooked.

 public void backToOrigin ()
     {
         float x = (vet[0]);
         float y = (vet[1]);
         float z = (vet[2]);
         cObj.transform.position = Vector3.MoveTowards (new Vector3(x,y,z), pos, step);
     }

Sorry my English.