class SGrade(TimeStampedModel):
    final_grade = models.DecimalField(max_digit=5)

class Comp(models.Model):
    subj_sched = models.ForeignKey(SubjectSched)
        name = models.Charfield(max_length=150)
        percentage = models.DecimalField(max_digit=5)

class Grade(TimeStampedModel):
    sgrade = models.ForeignKey(SGrade)
        component = models.ForeignKey(Component)
        grade = models.Decimal(max_digits=5)