Pete Grebner remembers what it was like to juggle a Como High School classroom with too many students, conducting chemistry lessons during which half the room did lab work while the other half read from a textbook.

He considers it a triumph that the St. Paul Federation of Educators secured class size limits in its tentative contract agreement with the state's second-largest school district. Until now, class size caps were routinely part of standalone memorandums of understanding between St. Paul Public Schools and its teachers union.

"It needed to be a permanent thing," said Grebner, now a teacher on special assignment for the St. Paul district and a member of the union's bargaining team.

Similar contract language is also up for negotiation in Minneapolis, where the teachers remain on strike. But if class-size caps are adopted there, the Twin Cities districts will be the first in the state to limit the number of students in their classrooms by way of contract language.

Districts typically avoid setting firm caps because sudden shifts in enrollment one year may require a school to hire another teacher, giving them less flexibility to adjust on the fly, said Kirk Schneidawind, executive director of the Minnesota School Boards Association.

"There's definitely a cost to the district by doing this," Schneidawind said.

The negotiations in St. Paul and Minneapolis echo a larger national conversation and reflect the scattershot approach to limits on class sizes.

In some states, including Texas and Arkansas, class sizes are dictated by state law. California caps enrollment in prekindergarten through third grade classrooms but allows unions to bargain on limits in upper grades. Until this January, Oregon barred teachers unions from negotiating with their districts on class sizes.

Grebner said educators were willing to strike over class sizes in St. Paul because they'd been a source of contention during contract negotiations for at least the last half-decade.

"Every contract, this was one of the top things," he said.

St. Paul district officials agreed to create class size committees in each school that will allow a teacher to negotiate the terms of accepting another student above the cap, according to the union. The teacher can ask for an educational assistant for support or any other number of resources to make sure the new student won't fall through the cracks.

"It's a way for us to acknowledge that there may be instances where allowing a class to go over the limit may be good for the program or a school," Grebner said.

Setting classroom caps

Negotiations continue in Minneapolis, but the St. Paul school board is poised to consider the tentative agreement ratified last week by the teachers union.

The agreement contains slight reductions to class size limits for some elementary teachers. Kindergarten enrollment in high-poverty schools can't exceed 24 students starting this fall. In first through third grade, that number is capped at 25.

St. Paul will also guarantee freshmen won't attend classes with more than 36 students. The cap for other high school classes will be 40.

Those caps are mostly in line with what was already spelled out in the less formal memorandum of understanding, lowering the class size of a few grades by a student or two.

In Minneapolis, class size limits will likely end up in the final working agreement between union and district leaders in the state's third-largest district, Superintendent Ed Graff said last week.

Minneapolis school leaders said in an update March 16 that the district had, for the first time, proposed including class size caps in the contract. Those caps would focus on core subject courses and in schools with the highest-need students, the district said.

Similar to St. Paul, Minneapolis educators also have a memorandum of agreement with limits on class sizes in high-poverty schools. It calls for the district to limit class sizes at those schools to 18 students for kindergarten through third grade and 24 students for fourth and fifth grade, but doesn't specify for older students.

And there's no such guideline in other buildings.

Time to teach

Cynthia Zwicky, who teaches in the undergraduate elementary education program at the University of Minnesota, said it takes loads of time and effort to build a relationship with students at the beginning of a new school year.

"To get to know a child well, if the child and I don't have a relationship, learning won't happen," Zwicky said.

In an overcrowded kindergarten classroom, for example, Zwicky said something as simple as getting a group of children out the door for recess is essentially five or six little lessons cramped into the span of three or four minutes.

The issues for middle- and high-school teachers are just as complex.

In a writing-heavy course, such as an English class, teachers spend as much of their time reading and grading as they do teaching. And if classes average 35 students, that's 140 kids if an educator teaches for four periods a day.

"Say you assign an essay. That's a hefty book you're reading," Zwicky said.

Both the Minneapolis and St. Paul school districts are losing students as families choose to enroll their kids elsewhere. Compared with the last academic year, Minneapolis is down nearly 2,600 students and St. Paul is down about 1,500, according to state data.

Grebner, the St. Paul teacher, pointed out that class size can be a selling point when families are choosing schools.

"If you look at the website for any private school and any charter school, what is the first thing you're going to see?" Grebner said. "Small class sizes."

Staff writer Mara Klecker contributed to this report.

Correction: A previous version of this story misstated Cynthia Zwicky's role in the University of Minnesota's College of Education and Human Development. She teaches in the department.