On the first day of his first job as a teacher at McLean High School yesterday, Dean Howarth, 22, stood in front of students only a few years younger than himself and urged them to enjoy his brand of physics.

"I hope to make this class kind of fun," the teacher in shirt and tie told the blue-jeaned teen-agers in his Fairfax County classroom. "It will be as easy as you want to make it."

As he spoke, one student turned to another and said teasingly: "He's already beginning to sound like a teacher."

Two months out of Virginia Tech and hired only three weeks ago, Howarth has joined a profession in flux. Higher salaries and national concern about the quality of education have raised the status of teaching after years of benign neglect. Many school systems are focusing new attention on their first-time teachers, who account for about a third of the new employes in Washington area school systems, in hopes of preventing burnout or poor performance later on.

"I haven't met anybody in teaching who didn't feel the first year was when it all came together or it all fell apart," said Sara G. Irby, Virginia's associate director of teacher education and certification.

Yet public school teaching also remains a career of lunchroom duty, interruptions by public address system announcements, and demands of bureaucracy that sometimes take priority over learning.

As might be expected on a first day, for example, virtually all of Howarth's day -- five class periods of basic physics for seniors, beginning at 7:30 a.m. -- was spent on paper work: signing out textbooks, filling out supply request forms, taking attendance, sending lost students to other classrooms.

"As soon as I get through the week, I'll be all right," Howarth said during his lunch break. "I just want to get to the point where I actually do something other than hand out books."

Despite his impatience with paper work, Howarth is a cheerleader for teaching, and it was his enthusiasm that helped persuade Principal Elizabeth Lodal to hire him. He made the 40-minute drive to school from his home in Laurel on Saturday to finish preparing his classroom, taping to the wall four-foot-high purple construction paper letters spelling "FIZZIX." He even swept the green speckled linoleum floor himself.

He is eager to have his students share his excitement for science: "I want to dare them to be bored. I want to say to them at the end of the year" -- he pointed to an imaginary student -- " 'See, you had fun!' "

"Physics is the study of motion, and the way things work," he told his sixth-period students. "My goal is to make it intertwine with your life. I'd like to make you scientifically literate, not just able to do equations."

He wants his students to like him, and chatted with them about high school sports and college life. Howarth also knows he needs to maintain the air of authority appropriate to his job. It isn't always easy.

"How old are you?" one girl in his class asked him.

"Twenty-two," Howarth replied.

"I go out with a 23-year-old," she said.

By the end of the day, Howarth was a better teacher than at the beginning. Instead of standing stiffly in front of the class, he strolled around the room or sat casually on a lab table amid his students. His speed at processing paper work had increased so much he had time left over at the end of each period.

"I feel like I'm a teacher," Howarth said after the end-of-school bell rang. "I feel like I have a place. It didn't even occur to me until I was in college that I wanted to teach. And now I can't believe how right a job it is."

Howarth was one of 336 teachers hired by Fairfax this year, 40 percent of them fresh out of college, out of 5,000 applicants. The county hired 100 fewer teachers this year than last, mainly because a 12 percent salary increase persuaded many veterans not to retire.

As a new teacher, Howarth will be paid $22,000 a year. Although his pay is higher than the national average of $18,000, friends from Tech who took engineering jobs will make nearly double his salary. He said he doesn't mind. "I'm fighting the good fight. Teaching is headed in a new direction," he said. "It's a noble profession no matter how much anyone puts you down."

Although yesterday was his first day with students, Howarth actually reported for work Aug. 28, attending a one-day orientation for new county employes. It is part of a new focus on first-time teachers that also includes an experimental county program pairing new teachers with experienced colleagues, a required state teacher competency examination, and a three-year-old state requirement that beginning teachers demonstrate on-the-job skills by the end of their second year in the classroom.

Howarth, the first in his family to attend college, never intended to become a teacher. He was headed for a research career in physics, his major at Tech, but he realized he had little interest in a sterile laboratory environment or in the amount of math it would require him to master.

Talking over his uneasiness with a friend one afternoon, Howarth realized the last time he really had fun in physics class was in high school. Why not be a physics teacher? He said he and his friend, also a physics major, marched over to the education school and switched careers that day.

Howarth's change of mind fits a trend. More college freshmen are expressing an interest in teaching these days, and although education majors traditionally have been among the lowest-achieving college students, Irby said Virginia's education school deans tell her that standards are higher now.

Although schools of education are widely criticized for alleged Mickey Mouse classes -- Virginia, for example, soon will require all would-be teachers to major in an academic field -- Howarth loved his education courses. He even appreciated being taught how to hold the chalk so it doesn't squeak on the blackboard. (Loosely, at a slight angle.)

And when he stood in front of a classroom for the first time as a student teacher in Salem, a suburb of Roanoke, he knew he had found his calling. "When you hear a kid say something like, 'I can't wait to have your class,' it really gives you a sense of self-worth," he said.