Floretta D. McKenzie, the new superintendent of D.C. schools, is a tall, husky, no-nonsense educator who says the school system should continue to set stiffer promotion standards for its students and maintain former superintendent Vincent E. Reed's emphasis on basic skills in reading and math.

But McKenzie, 45, a graduate of Dunbar High School here, also says she wants the schools to offer more programs of gifted students and for those city childen lured to private schools during a decade of consistent low achievement in the public schools.

Her first chore as head of the troubled 99,000-student system will be to look at the system's shrinking budget. She said she believed this year's budget was inadequate and she might use her contacts in the federal government and private foundations to find more funds for the schools.

"You can't treat the school system like any other city agency. You can't attract people to your city if you don't have a good school system," she says.

It is a large order to fill, McKenzie said yesterday while frying potatoes in the kitchen of her modest, two-story, red-brick home in the solidly middle-class Michigan Park section of Northeast Washington.

But, "I've lived here 30 years. I've been in this house 22 years. It's not like I'm a stranger to the city or the schools," McKenzie explained in the stern-sounding, clearly articulated tones so common to teachers. "I think people know of my very sincere commitment to the public schools and to children. I just really did kids. . . . I have a feeling for the schools."

McKenzie is one of the youngest superintendents and the only one in recent memory to have attended D.C. schools. She is the system's fifth superintendent since 1967 and the second woman to hold the job, although she was the first to have it in an acting capacity.

The D.C. school board selected McKenzie late Wednesday night, after four boards members tried unsuccessfully to block her appointment by proposing to extend the term of Acting Superintendent James T. Guines.

Only three boards members did not vote for McKenzie -- John E. Warren (Ward 6) and R. Calvin Lockridge (Ward 8) abstained and Frank Shaffer-Corona (At-Large) voted present.

In an unprecedented move, the board has also made her sign a "letter of understanding" in which she agreed to be evaluated twice a year. She will receive a rating based on improvements in student achievement.

Friction with members of the board was one problem cited by Reed when he abruptly resigned late last year. McKenzie said she was not worried by the fact that three members did not support her selection to the $55,400-a-year post. "I think it's only normal," she said of the opposition. "I look forward to working with all of the members of the board."

Those who know her say Floretta Dukes McKenzie can be aggressive, strong-willed, tough and sometimes volatile. But they also say one of her strong points is her ability to deal with people.

"She's a person who will go right at an issue. She's not afraid to make decisions. She's tough," said Reed, who has been nominated to be assistant secretary of secondary and elementary education in the U.S. Department of Education. Reed said he worked closely with McKenzie when both were in the secondary schools division of the D.C. schools.

Blair Ewing, a school board member in Montgomery County where McKenzie was the deputy superintendent until 1979, recalled how she was caught in the middle of a long-running battle between some of the Montgomery board members and then Superintendent Charles Bernardo.

"She must havebeen feeling a great amount of discomfort then . . . But she was able to remain loyal to [Bernardo] while simultaneously being courteous to the board. I thought that was the mark of a real professional," Ewing said.

"She is a real person who communicates clearly and effectively," said Edward Andrew, Bernardo's successor as Montgomery superintendent. Her style is to work with people. That's how she gets thing done."

Anitsa Cordom, a counselor in the Montgomery schools, recalled how a firm-minded McKenzie used to tell the principals working under her, "You've got to keep your staff on their toes. You've got to keep the troops fired up."

Cordom, a District resident who sends her children to the D.C. public schools, said she felt McKenzie "always had the children's interest at heart. She would cut through the red tape when necessary to get through a program she believed in."

Unlike some D.C. superintendents in the past, McKenzie said she does not intend to come in with a huge plan for reorganization. "People appreciate it when there's not too many surprises" she said.

Most of all, she said, she wants to hear the ideas of the people already working in the system. "That's one of the major reasons why I won't come in with specific proposals," she explained.

"Generally, we will go with the plan that's there," McKenzie said. The new stiffer promotions standards for elementary students and the competency-based curriculum, both of which started under Reed, were "showing some good results," she said, but added that these programs must be "continuously evaluated and modified if necessary."

The District's competency-based curriculum stresses reading and math and requires students to master certain objectives in each course. McKenzie is familiar with this increasingly widespread method of teaching since she headed Project Basic, a program to develop minimum competency tests for high school graduation, when she served in the number three position in the Maryland State Department of Education.

Throughout her career, she has been involved in programs to push students on to higher academic achievement. In the 1960s, she headed a project sponsored by the College Board to identify and encourage low income youths in the District to attend college.

She also helped set up a program in the early 1970s in which the Ford Foundation paid for all juniors in D.C. high schools to take the preliminary college board exams.

Mayor Marion Barry said he felt McKenzie would combine in her new job her "valuable experience at the local, state and federal levels with an outstanding record in the District public school system."

Barry, a former school board president, said he would meet with her Monday "to discuss our mutual interest and concern about the quality of education in our public schools."

McKenzie made her first public appearance since her appointment yesterday morning at the graduation ceremony at the Burrville Elementary School on Hayes Street NE. She received a standing ovation from the 300 parents and teachers gathered in the audience when she was introduced, according to principal Walter Henry. Henry said he had asked McKenzie to give the commencement speech several weeks ago. The theme of her speech, he said, was "Striving for Excellence."

Yesterday, the phone in her home rang incessantly with calls from well-wishers and the press. A dozen roses arrived in the late morning.

One of her main objectives, McKenzie said, would be to "build up community support" for the public schools.

Toward this end, she said she intends to continue the Operation Rescue volunteer tutoring program, which this year found more than 1,000 persons to help students with their studies.

"It's unfortunate, but we don't value the public schools as we should," she said, adding that "these people who go through the public schools are the backbone of our country."

A native of Florida who came to the District as a teen-ager and one of six children in her family, McKenzie received her bachelor's degree from D.C. Teachers College in 1956. She majored in history.

She received a master's degree from Howard University and took doctoral courses in history at American University, but does not have a doctorate degree.

She received a commendation for " Outstanding Performance" from the school board in 1973 and that same year won the Mayor's Distinguished Service Award.

McKenzie's husband Donald is a piano technician with the D.C. school system. They have a son, Kevin, 19, who is a graduate of McKinley High School in Northeast, and a daughter, Donna, 17, who graduated this month from Wilson High School in Northwest.