When it comes right down to it, the size of a classroom and what happens inside it is more likely to affect a student’s performance than the size of the school district that the classroom is part of.

That becomes even more evident when one realizes that the size of districts varies greatly from state to state and region to region. Some follow municipal borders, some are aligned with county boundaries, and some district boundaries seem to have no relation to the municipalities that are part of their districts. In addition, some systems are unified and have students in grades K to 12; other areas have separate systems for elementary and secondary students.

Still, the vast amount of numbers contained in the National Center for Education Statistics’ preliminary enrollment numbers for 2010-11 provides some insight into how schools are organized and where growth is occurring.

-The 100 largest school systems represent 7/10ths of 1 percent of all U.S. school districts, but in 2010-11 they accounted for 22.4 percent of the nation’s public school students (10,766,141 out of 48,085,879).

-Three states—Florida, Texas and California—claim 45 of the districts on the list. No other state had more than six.

-Florida, with 14 districts among the top 100, accounted for the most students among the 100 districts (1,872,182). Those 14 districts also account for 71 percent of the public school enrollment in Florida, which has countywide school districts.

-With 19 districts, Texas had the most school systems in the top 100. Those 19 districts accounted for 1,492,024 students, which represents about 31 percent of the state’s public school enrollment.

-California has 12 districts among the 100 largest. They accounted for 1,391,463 students, which is about 23 percent of the state’s public school enrollment.

-Twenty-two states had no districts among the 100 largest.

-The number of districts in any given state ranged from one (Hawaii) to 1,031 (Texas).

-Districts of 100,000 or more students accounted for 12.3 percent of the nation’s public school enrollment. Districts of 10,000 or more accounted for 54 percent of public school students.

-The district among the 100 largest that grew the most from 2000 to 2010 was the Loudoun County (Va.) system, which virtually doubled, from 31,804 to 63,151.