A problem with previous grading systems I had used was that it was possible to pass, even achieve an A in, a math course and not learn some key content. A student could totally miss factoring polynomials for example, but if they did well on the other content they would pass. However, since math builds on itself so much each year, missing content could be a stumbling block in future classes. To combat this I set the minimum passing standard to be demonstration of EVERY content standard at a basic level.
I broke the content of the courses into about 50 standards which I considered core to the course. I also included some key content from previous courses. See (Math 10 Core Standards, and Math 11 Content) These were to be assessed on daily quizzes. (See example) To demonstrate a standard a student had to get a question on the standard correct on two different quizzes. This was a middle ground between only having to show the standard once (which I didn’t feel would be enough) and making the demands on students too much. If a student has not demonstrated all the standards on quizzes, they could take reassessments on the specific standard they needed.
50% of a student's grade was determined by the content standards, but it would either be a grade of 100% (if all were demonstrated) or 0% (if any were not demonstrated). Thus demonstrating all the content standards was a necessisary and sufficient condition for passing. The distiction between grades above passing was determined by the other 50% of the grades which come from tasks, tests and online practice (Delta Math).