0 = 0, or so I have ever been told.
In most cases and with standard mathematics I would have been proven correct. Indirectly the school system decided against this notion.
The standard grade scale for students in the U.S is A, B, C, D, F, with A being the highest and F being the lowest. Within that scale, there is a subscale that creates the letter grades.
Typically, 
The first thing that should jump out is that all categories are divided into ten point increments except for F. There is a 59% chance of earning an F while there is only a 10% chance of earning any other particular grade. To go even further, only 41% of the scale will award a passing grade. The state of Florida has a Grade Point Average (GPA) requirement of a 2.0 for graduation. A 2.0 is the equivalent to a C. So, in actuality, the grade scale is skewed 30/70 in favor of a grade not worthy of graduation. 
Things seem skewed in the wrong direction.
The first argument against my claim is that students are in control of their grades. This is 100% accurate and I couldn’t agree more. But, even the best students have a lapse in judgment or experience teenage forgetfulness. Given that this occurs more than we would like, should the student’s entire body of work be wrecked because of one assignment?
When a student receives a zero the impact is almost unrecoverable. See for yourself.
I believe that students should be held accountable for all assignments turned it, or not turned in, and quality of work is essential. By no means am I trying to give students a free pass to getting higher grades. What I am stating is that the absence of one assignment should not turn an A student into a D student in the gradebook.
If our goal as educators is to motivate and teach students, why would we have a grading scale that is skewed to fail and discourage?
I propose that if we must have a grading scale, that the one we choose is fair. All grade categories should be evenly distributed it. If the range for an A is 10 points then so should a F. Such a system would allow for greater grade recovery efforts.
Danny, do you realize how many lives would change if we changed the grading system to what you are proposing? I agree with you and see so many students get defeated when one grade has destroyed their hard worked for, “A”. We encourage students to do their best at all times and if they do, why are we punishing them with such a skewed grading scale? Our elementary schools grade on a performance rating scale. I wonder how long it will take to bring this type of grading to the secondary level or if this can be infused with the letter grades students are currently receiving, minus the “f”?
Since this topic became a conversation several years back, I began to look at ways to apply the principles involved. I could not get away from using other numbers, but I began by lowering the actual integers and using grade categories as a means of leveling the assessment floor.
One grade I created was an “N” for not quite. The value is 40%. It has a detrimental impact, but does not obliterate an average.