Nearly 270,000 students are expected to return to their classrooms next week in Montgomery and Prince George's counties and in Howard County, which has the fastest growing school system in the state.

Schools open in Montgomery and Prince George's on Tuesday and in Howard County on Wednesday.

"Educational equity" will be Montgomery County's most important theme for the 1978-79 academic year, according to Superintendent Charles M. Bernardo. New programs in the county's 186 public schools, he said, will focus on minorities and unmotivated students. "We will dedicate ourselves to reducing (educational) gaps between blacks, whites and females," Bernardo said.

Bernado predicted that 108,000 students will be attending county schools. That figure is 4,000 students fewer than last year's enrollment.

As part of the declining enrollment picture in Montgomery County, three junior high schools have been converted to middle schools (grades 6, 7, and 8) will open next week. The middle schools represent another stage in the continuing reorganization of the county's elementary, junior and senior high schools.

In Prince George's County, where enrollment is projected to drop 4.3 percent, 133,346 pupils are expected for classes Tuesday. The county's school system will have nearly 19,000 empty classroom seats in elementary schools alone. The process of considering additional school closings resumes shortly.

Mastery of basic skills remains at the heart of the Prince George's County school system, which is the 10th largest in the nation. For the past year, school officials have been trying to perfect a comprehensive program that will stress functional reading skills. The county's 6,600 school teachers are ready to test the reading program now, said John Aubuchon, school spokesman.

"It's a time for refinement," said William Blount, administrative assistant to the superintendent. "Not a lot of new programs, but we should be improving the ones we have now."

Apprehension and pessimism cloud the outward enthusiasm of school officials for this fall's school opening. Officials in both counties say they have adopted a wait-and-see attitude toward tax limitation proposals that have been placed on the November election ballots in Prince George's and Montgomery counties.

In Montgomery County, there are two proposals - one that would cut county property tax rates by as much as 15 percent and another that is designed to control county government spending. Prince George's County has a proposal that would freeze the county's total annual property tax collections at this year's level, predicted to be $140 million.

"While we are excited about dedicating ourselves to educational equity and other new programs," Bernardo said, "we will be doing all this under the pall of negativism that is spreading across the nation. I hope homeowners see through the economic and social insanity of extreme tax limitation and spending proposals."

The local tax and spending limitation proposals follow the success of California's Proposition 13.

While Bernardo predicted that the Montgomery County school system's $268 million operating budget could be chopped by as much as $50 million if either measure were approved, Aubuchon declined to speculate on the potential impact of tax limitation in Prince George's County.

"We are not prepared to make any assessments," Aubuchon said. About 50 percent of the school budgets in both counties comes from local govrnment revenues, which receive their major source of revenue from property taxes.

Meanwhile, in Howard County, Superintendent M. Thomas Goedeke said he is expecting a 1.6 percent increase in enrollment. Between 1972 and 1976, enrollment increased 17 percent while the number of students in the state's school systems as a whole decreased 3.4 percent.

Nearly 26,000 students will attend Howard County's 47 public schools, two of which will open for the first time Tuesday.

"This is going to be one of the best years we've ever had," Goedeke said. "We've been able to be very selective in choosing faculty because we've had so many applications for positions." About 1,400 teachers will begin the fall term, about 40 more than last year," he said.

The county's $47 million budget for school operations was increased by 12.8 percent for the 1978-79 academic year, the first time that the school system's proposed budget was fully funded, according to Goedeke.

Hammond High School, located just outside of Columbia, will be the pilot school for a new program dedicated to students who seem unmotivated. Teachers will be paying extra attention to 32 of those students in the mornings. Each afternoon, those students will learn trade skills at various jobs throughout the school year. Thirty additional students in various other schools throughout Howard County also will participate in the program.

Montgomery County students can hope for warmer weather during their spring break next year - the 10-day vacation period has been restored to April 9-16. Last year schools closed for spring recess in mid-February to save fuel.

Children who will be 5 years old by Jan. 1, 1979, are eligible for kindergarten. Elementary school students are usually registered by each school during the last two weeks of August and throughout the school year. Secondary school registration may be done at any time of the year.

All children between the ages of 6 and 16 are required by state law to attend school. A birth certificate and immunization record must be presented to enter school for the first time. Pupils who have attended school elsewhere should bring a report card from their previous school.