IF FORTUNES hold, one of the three Rs for Washington public school teachers should soon stand for "ratify"--which they should be eager to do to the tentative agreement just reached with the school board for a new three-year contract. And if that happens, it should spell relief, not only for them, but also for everyone else interested in the public schools here. There are improvements for all involved, even--if you can stand it--students.

Nothing drastic is in the offing for anyone, but some important principles have been agreed to. They include a longer workday, a longer school year for teachers and a higher standard of performance to qualify for a scheduled pay increase in the sixth year on the job.

To the many dedicated teachers who already volunteer their time to students before and after school, an additional 15 minutes at each end of the day won't make any difference. But to the students, who have watched some of their teachers pull out of the school parking lot before the last class is out the door, it looks as if help is on the way. Similarly, the requirement that teachers earn a better-than-satsifactory rating to receive their sixth-year pay increases will not affect many of today's faculty members; but it is an important step in establishing higher standards as a prerequisite for advancement in the future.

For the teachers, there are provisions allowing them more latitude to protest job performance ratings they receive from the principals who supervise them. Under the current contract, for example, a teacher who has received anything better than "unsatisfactory" may not object or argue for, say, "outstanding" instead of "very good." But in times of layoffs, these higher ratings do make a difference.

As School Superintendent Floretta Dukes McKenzie noted in her Close to Home commentary yesterday, teachers as well as students, should profit from teachers' extra four days each year--time that, if used wisely, could provide opportunities for new training, course work and other forms of professional growth.

So there are rays of hope for the D.C. schools and their young charges. With a vigorous and popular superintendent, a more serious school board, a reasonable budget and teachers who care about their jobs, Washington's public school children may finally have a fair shake at the education they deserve and must have to be tomorrow's job holders and community leaders.