Classes are back in session on the Treasure Coast. Let’s see how our schools are doing. During the summer, the Florida Department of Education posted the grades it gave this year to the state’s 67 school districts. For the 11th year in a row, the Martin County School District received an A. It was ranked fifth in the state. Congratulations, Martin County! But Indian River received a B after four years of A’s, and St. Lucie received a C after four years of B’s. Not much cheering in those districts. The district grades are based primarily on FCAT scores. That’s F-C-A-T for Florida Comprehensive Assessment Test, which measures student proficiency in math, science, reading and writing. This year FCAT scores were down in many Florida districts because the tests are harder and the grading formulas were changed. After releasing the school district grades, the state Department of Education said, oops, we miscalculated the grades for 213 schools statewide. Most of them should have received higher grades. One was in Indian River County and two were in Martin County. Let’s hope the grading goes more smoothly next time. Or else the public may give the Department of Education an F.