More than 84 percent of the elementary school students in the D.C. public schools received mid-year promotions, an increase of 11.4 percent over last year's midterm mark and a reflection of higher achievement levels in reading or math skills, the school system said yesterday.

The increase represents the highest percentage of promotions among the 36,674 elementary school students since the school system implemented its more rigorous "Student Progress Plan" for student advancement in the fall of 1980. Students at each grade level must master 70 percent of the plan's requirements for reading or math skills each semester before they can be promoted.

School officials said yesterday they could not say how many of the 30,850 students promoted in January had mastered both the reading and math skills, and that that information will not be available until a final promotions report being prepared for the board is completed.

Students who meet only one standard or who fail to meet either standard receive special tutoring and must attend after-school programs designed to bring them up to grade levels.

Slightly less than 73 percent of the city's elementary students were promoted under the plan in January 1982, when it for the first time included fourth through sixth grade students. Of those promoted, 8,902 (22 percent of the elementary students) met the required level in only one of the two areas.

This year, fourth, fifth and sixth grade students recorded the greatest improvement, from only 64.2 percent promoted in January 1982 compared to 83.7 percent last month.

D.C. School Superintendent Floretta D. McKenzie gave the promotion results to school board members in a closed meeting yesterday. She said the promotions have increased because more students have worked under the student progress plan for at least three semesters and are more familiar with it.

McKenzie also said the school system in the last year has hired 124 special resource teachers who specialize in elementary level reading and math, hired 73 other elementary teachers to reduce class sizes, and spent $662,940 for computer based instruction.

"We are very pleased with the results. It shows that people are indeed engaged in the major mission of this school system, teaching students to learn," said McKenzie.

School board members said they will use the increased promotions figure in arguing before the City Council for more funds for their fiscal 1984 budget. Mayor Marion Barry has proposed $18 million less than the $336.4 million the school system wants.

The student progress plan was intended to give teachers objective criteria to evaluate students' performances. Before it was implemented, according to James T. Guines, the school system's associate superintendent for instruction, promotions were frequently based on the often arbitrary decisions of each school or instructor and failures were running at about 10 percent.

In January 1981, after the Student Progress Plan was implemented for grades one through three, only 68.2 percent of the students received promotions, according to school system statistics. Last January, 80.9 percent of those students were promoted, and this year 84.5 percent of the students in grade one through three were promoted.

No school-by-school figures for promotions were available yesterday.

The new promotion figures were released at a time when the board has begun to evaluate McKenzie's performance after 18 months as superintendent.

By Feb. 24, each school board member will complete an individual written evaluation of McKenzie using criteria based in part on a letter of understanding McKenzie signed when she accepted the post in July 1981. The results of the individual evaluations will then be tallied by the board's staff.

The board members will use a nine-point scale to rate McKenzie on, among other things, her success in strengthening the system's competency-based curriculum, increasing student performance and punctually keeping the board informed on budget and other matters. The members have been asked to rate the superintendent as below average, average or above average in each category.

McKenzie, at the board's request, has submitted a written account of steps that have been taken to meet the goals laid out in the evaluation criteria. In that document she said she has improved the report card system, streamlined student achievement criteria, produced higher standardized and achievement test scores by students, involved parents more in their child's instruction by producing a handbook on student achievement, and streamlined administrative personnel.