Math teacher Steve Beninghove estimates that during football season he puts in 45 extra hours a week coaching the varsity team at Mount Hebron High School.

For this work, which also ties up his summers with practice sessions and weight training, he is to be paid $2,500 in the coming school year -- that is, if Beninghove and about 100 other Howard County coaches don't carry out their threat to strike over pay this fall.

The county school board, which recently granted the coaches a 35 percent raise over the next three years, has turned down the coaches' demand that wage negotiations be reopened.

Coaches contend that they have been slighted during contract talks over the past decade on general teacher salaries. They are demanding that the board pay them by the hour for their extracurricular work. In Montgomery County, football coaches paid an hourly wage make more than $4,600 a season, according to Howard County coaches.

"We have a lot of people who think it's an honor to coach and that we should do it for nothing," said Beninghove, 42, who also coaches junior varsity lacrosse at Mount Hebron.

"They think you really love it, so you should do it for free. But I have three kids who would love to see me at home. It's important that I get paid for my time away," he said.

School Superintendent Michael E. Hickey told representatives of the coaches association last week that he supports the concept of hourly pay, which could double some stipends for coaches of high-profile games such as football. Hickey also told them that $55,000 diverted by the school board from the athletic equipment fund for band uniforms will be restored next year.

Coaches are scheduled to be paid $1,625 to $2,500 for their duties in the 1990-91 school year, compared with $1,031 to $1,375 for other extracurricular activities such as advising the school newspaper staff, serving as class sponsor and advising the math team.

The anger of the coaches and of parents of student athletes has been growing since the school board made it clear earlier this year that it would not bargain separately over coaching stipends. More than 100 people turned out to press the board for more money last week, describing coaches as hard-working role models and motivators for students. But the board said it would not reset the salaries.

In previous years, "We've cut a lot of money from the music budget, from summer school" and other valued programs, said board member Ann L. Dodd, defending the recent budget actions. "I can remember cutting so many things that were so difficult -- and yet at the time we didn't cut athletics."

One indignant parent of Atholton High School students said, "The importance of athletics is like motherhood and apple pie in America. I'd rather have a kid on the field than snorting coke."

"This sends a message that we're not really important," Mount Hebron coach Dave Greenberg said after the meeting.

In Howard County, 40 percent of the high school athletics coaches come from outside the teaching ranks. And of those coaches who are full-time teachers, more than half are from outside the physical education departments.

With 33 teams in every high school and only three physical education teachers assigned to each school, the school system has been hard-pressed to find coaches, team sponsors said.

Howard coaches have tried to get the school board to add money to the athletics budget for trainers, saying that they need personnel to help prepare students for safety and conditioning.

"One of our concerns now is that a great many of the people that are currently coaching are not teachers," said Stephen Carnahan, cross-county coach at Oakland Mills High School. "We have lost the incentive to bring teachers who are in the building into the coaching ranks . . . .

"A teacher could go to Giant Food and make a whole lot more money at a part-time job with far fewer responsibilities," he said.

Coaches "resent being taken for granted," he added. "After the season we get the pat on the back and are told we're doing a great job, but when negotiations come around we get slapped in the face."