I did not calculate it to that degree - nor could I spend that much time doing it. It came years ago from a DNA calculation book which included the example. They definitely did not have to make as many assumptions as you do to believe in evolution - as it is currently presented.
I do have lots of information on DNA that I could send you - if you are interested in it. It's pretty dry reading material, but it is pretty clear that DNA does not mutate like the old textbooks claimed in support of evolution.
Ok, ignore the fact that something cannot come from nothing. Show an example of an inorganic object becoming a living organism (creation of life) from inorganic matter through the scientific method, and the utilization of the scientific method to observe the natural creation of a new species through DNA mutation.
So, you choose to trust a random person who you cannot name, question, research, etc? Care to buy a bridge in Brooklyn? It's cheap..
I would hope that you would question everything told and taught to you - however, that being said, there is no real harm in you believing something that does not daily impact your life. Like I said earlier, it is all about faith. I personally cannot have faith in something that defies probability to such an extent as the current theory does, but whether I believe it or not does not affect my daily decisions either of how I provide for my family.