I wouldn't worry about the grades so much in the younger years. My son's former school (that was Pre-K through 3rd grade) was a bit alternative. The school provided a "term report" twice a year that was 10 pages long, and used a grading legend of 'Well Developed", "Developing", "Beginning to Develop", and "Not Yet Apparent". It applied those grades to about 10-12 'learning skills' in each subject, but did not give an overall grade in any subject. The school never gave standardized tests either. My son had no problem in applying to private schools for 4th grade. The private schools did their own evaluations or required testing. I think private schools are used to considering a number of different grading systems.