How grades are calculated. you can choose Natural or Highest, and Natural is the right choice in most cases.
Natural weighting: the default way to aggregate grades. It sums up points (and will show you weights that tell you what percentage of the course total those points represent), unless you customize the weights.
(Selected by default) If checked, empty grades are excluded from calculations and don't count against students. If this is unchecked, empty grades are calculated as "0" and your students may be alarmed by low course totals early in the semester.
: Exclude one or more grade items with the lowest value from being calculated in the category total. NOTE: you can drop lowest grade(s) ONLY if all of the items in the Grade Category have the same maximum points.
Value (grade type) : the grade type for a numeric grade.
Text (grade type) : the grade type for textual feedback.
Scale (grade type): the grade type for descriptive scaling like good-fair-poor or whatever scale you define.
None (grade type) : an assignment that cannot have a grade assigned.