Making sure two-thirds of education money goes to the classroom isn't a math problem -- it's almost a philosophical problem. It's all about how you define instructional spending. State leaders want educators to get 65 percent of every dollar to the classroom. The state has a definition of that, and the results are posted on the Texas Education Agency's website for anyone who wants to dig around and find it. The National Center for Education Statistics has a definition, too, and it's the one backed -- at least for now -- by Gov. Rick Perry and some others in state government. But there are big differences between what Texas has labeled as instructional spending and what the feds have chosen. Deciding on what to include has fallen to the TEA, and to task forces of school people and civilians assembled for the arguments. We plowed through the state's own statistics a couple of weeks ago to look at this based on the state numbers. Since then, the TEA has ranked the state's schools as if the NCES standard was the law of the land. The results are, well, different. We charted their numbers under each of the two definitions for every school district in the state. You can get the listings -- in Adobe Acrobat or spreadsheet form -- in the files section of our website. The overall results are similar. With the state's Academic Excellence Indicator System, the average district spends 64.8 percent of its money on instruction. Using NCES, that's 64 percent. Inside those averages are big differences. Use the state's numbers and all but three of the biggest school districts in Texas are over 65 percent; use the national numbers and 14 of the 25 don't hit the mark. Only 250 of the 1,037 school districts spend 65 percent or more of their money on instruction using the state definitions, but those districts teach 59.6 percent of the state's students. The state definition is kinder to bigger districts. More Texas districts make the grade using the national definition -- 424 -- but they educate only 38.9 percent of the state's public school students. Why the swings in results? Both AEIS and NCES (which is part of the U.S. Department of Education) include salaries for teachers, aides, substitutes, special education teachers, physical education, and costs of instructional materials and equipment used in classrooms, textbooks, band instruments, computer labs and supplies, testing materials, and insurance for drivers' education vehicles. That's all in a category designed to include everything that deals with direct interaction between teachers and students. If you read the broad categories that are and aren't included, it's harder to see what the fight is about. The devil's in the details, some of which are listed here. TEA includes several things the feds leave out, in three broad categories. • Library and resource centers: Librarians, aides and assistants, people who run instructional media areas and equipment, those who write and produce those programs, and books and films and tapes maintained in a school library. • Curriculum and instructional staff development: In-house and outsourced staff development personnel, travel for staff instruction, substitutes who fill in while regular teachers get training, certain tuition and fees and other costs of outside training for teachers, paid sabbaticals for instructors, and administrators who solely oversee curriculum. • Student guidance and counseling: student testing, mental health screening, psychiatrists, psychologists and diagnosticians, guidance records and record-keepers, placement services, and parent/teacher counseling. NCES doesn't include those things, but does include costs from three categories the state doesn't include. • Extracurricular activities: Coach salaries (above what's already included for P.E.), assistants and trainers, insurance to cover student sports injuries, athletic supplies and equipment, referee and umpire pay, travel and lodging for traveling athletes, coaches and staffs, for band directors and debate coaches and the like, and band uniforms. • Shared service expenses and salaries. • Costs of juvenile justice alternative education programs. Education Commissioner Shirley Neeley has a group of educators worrying over the definitions, and another group made up of people who aren't in that business. Gov. Perry wants TEA to come up with a 65 percent rule -- with exceptions for districts with unusual problems like high transportation or special needs costs -- that it can impose on public schools all over Texas.