READY OR NOT, Washington's public schools are scheduled to reopen on Thursday -- and right off the bat, the whole system will be put to a stiff test. With hundreds of classroom teachers laid off since last year, schools in every corner of the city will be scrambling to match new teachers and in some cases drastically reorganized faculties with altered curriculums, reduced administrative staffs and shrinking student bodies.

Although a certain amount of confusion seems accompany the opening of District schools in any year, the latest teacher upheaval has been the most acute in seven years -- and principals are going to have to hustle to set their buildings in order on time.

The most serious situations are in the elementary schools, where the greatest layoffs occurred, and where the child-teacher personal relationships tend to be most important. In some of these schools, as much as half of a faculty may turn out to be made up of teachers transferred from elsewhere, with different skills, specialities, and working habits. This may not be an attractive prospect, but neither must it be all that traumatic an experience; resourceful principals and helpful faculty veterans can do much to orient new teachers as well as reassure anxious students and parents.

There may still be additional attempts to reinstate some of the dismissed teachers through retirements and various money-saving plans, including payless furloughs. But the cold facts are that the District's public School population has declined -- by 6,000 since last year, for a total of 97,900 students at last count -- and that the city's financial picture dictates some serioous belt-tightening throughout the government. The city's school board could cushion some of the blow in the elementary and high school classrooms by closing down underused facilities and/or reducing the scope of pre-kindergarten, all-day kindergarten and adult education programs. But in the absence of a board majority that can act decisively, seriously and in any genuine harmoney, the job of making the best of austerity will rest in the neighborhoods.