Gone are the days of exuberant growth, a steadily expanding staff and innovation wherever a bewildered parent looked. Instead, Montgomery County school officials are taking a more cautious approach. They seek to shore up existing programs, to restate a commitment to basic instruction and to build up morale under Superintendent Edward Andrews, appointed July 1 to a four-year term. Some of the changes students returning to school on Tuesday might discover include:

Total enrollment at its lowest since 1963. An estimated 96,926 students will attend the 181 schools in the county, down from 102,380 in 1979-80.

Fewer teachers to greet them. There will be 309 fewer school employes than last year, 255 of whom are teachers. Due to attrition, only 31 teachers were laid off.

Emphasis on instructional programs. At Superintendent Andrews' urging, more school time will be spent by administrators and teachers on the learning basics.

Four schools closed in the past year -- English Manor, Larchmont and Grosvenor Elementary Schools and Randolph Junior High. Long-term leases on the elementary schools will be transferred to the county, while the junior high will be used for county and school offices.

Changes in the senior highs. A new senior high policy, with more stringent attendance requirements and the uniform countrywide final examinations, will be instituted in September. In addition, all 22 high schools will have a six-period day. Half of the high schools had operated on a seven-period day last year.

One new face or more on the Board of Education. Elections will be held Nov. 4 for the seats now held by Blair Ewing, Marian Greenblatt and board president Daryl Shaw. Shaw chose not to run for re-election.

Slight price increase for lunch. The hot lunch remains 55 cents for elementary students and 60 cents for high school students. A half-pint milk portion will cost 15 cents, up from 12 cents. Other a la carte items average a 4.5 percent increase.

Perhaps the most startling change for most students will be the simple shock of another summer vacation ending. But while students were out of school, administrators were working to smoothly incorporate the above changes into the Montgomery system.

Declining enrollment, for example, has meant that the steady stream of school construction that characterized the high-growth 1960s and 1970s has almost stopped.

No new schools will open this year, nor have any since 1975, when three schools started operating in the upper part of the county. However, Martin Luther King Junior High is slated to open in Germantown in September 1981.

School closing was one of the stickest issues adminstrators and board members that lasted hours between board members and angry parents were common as school to close.

The parents of children at Grosvenor School in Bethesda are still fighting the local board's move and have appealed to the state board to overturn it.

A task force is expected to work on a comprehensive school closing policy in the coming year. No decision has been made whether to close additional schools, but chances are, as enrollment continues to decline, school closings continues to decline, school closings will have to be faced again.

In terms of programs, administrators have called for a renewed emphasis on instruction and back-to-basics learning. One way this will be accomplished is through a controvesial senior high policy which more strictly limits class absence and institutes uniform countywide final examinations.

After years of study and discussions, the school board voted 4 to 3 in favor of the new policy. Dr. Paschal Emma Montgomery Blair High's principal for 15 years, has been designated the assistant superintendent charged with implementing the policy.

As often happened in the past year, a rough conservative-liberal split occurred with the more traditional members -- Joseph Barse, Marian Greenblatt, Carol Wallace and Eleanor Zappone-supporting the new policy and Blair Ewing, Elizabeth Spencer and Daryls Shaw opposing it.

That split might change, however, in the next few months. Elections for the seats now held by Ewing, Greenblatt and Shaw takes place on Nov. 4. Besides Ewing and Greenblatt, Suzanne Peyser, Sandra King-Shaw, Marilyn Praisner and Michael Goodman received the honest number of votes in May's primary to run in November.

The board also voted to consolidate the five administrative areas that make up the Montgomery County school system into four, which will result in a shift of administration personnel next January.

School officials say this will have no effect on school boundaries or feeder patterns, and that the links between the area and central offices might be strengthened. But the fact is that the move came about when the Montgomery County Council slashed eight area administrative positions from the education budget.

The council approved in $309.1 million budget for fiscal year 1980, an increase of 8.9 percent over last year. While the per capita cost of educating each Montgomery County student grew, this was mostly due to a cost-of-living pay raise for the system's employes.

It is estimated by the school system that it costs an average of $2,875 to educate a Montgomery student, up $380 from $2,495 in 1979.

A budget-saving device was the elimination of the seven-period day in all 22 county high schools. Students will now have six periods a day. Last year half of the schools broke their day into seven periods. One immediate result is that some students can no longer choose as many electives.

State law requires that all children ages 6 to 16 attend school. Those who are 5 years old on or before Jan. 1 may attend kindergarten.

To find out at which school a child should register, call 279-3333. Children entering Montgomery schools must show evidence of immunization against diptheria, tetanus, pertussis, polio, rubeola and rubella.

Foreign students need to register at the International Students Admission Office at the former Randolph Junior High in Rockville (770-7600).

Parents can transfer their child to another school outside his or her normal attendance area if it's considered in the child's best interest, if the racial and socioeconomic balance of both the new and old schools won't be adversely affected and if the new school has adequate space and staff.

Throughout the year, emergency school closings are announced on WINX (1600 AM), WMAL (630 AM), WPGC (1580 AM, 95.5 FM) and WFMD (930 AM)/WFRE(100 FM).

Call 279-3673 for a taped message of current school events. For Other information, call 279-3391.