Nic Savinar tried to maintain a measure of normalcy for three days in her fifth grade classroom at Centennial Elementary School in northwest Denver, even as her students asked awkward questions about why she was still there when most teachers were out.

Walking in the door, she had a fleeting thought that someone from outside the school community might join the picket line and lash out at her. Her fellow teachers marching in the cold lent nothing but support, sending her texts throughout the day checking in.

Then not long after 6 a.m. Thursday, word started getting around that the Denver teacher strike was over. Principal Laura Munro’s phone blew up after her morning Crossfit workout. Munro ended up getting to school late because excited teachers kept texting her.

With the three-day strike about teacher pay ending with a tentative deal that gave both sides reason to feel good, Denver schools spent Thursday in a strange in-between place as substitutes and central office staff fill-ins reported for duty and striking teachers returned.

The labor action and its sudden conclusion posed a test for the 147 district-run schools affected by the strike and the 71,000 students in grades K-12 who attend them. Centennial just a few years ago was at risk of closure due to persistently poor academic performance. The school started to turn around after it reinvented itself in 2013 as an expeditionary school, where teachers in each grade weave a year-long “expedition” theme into their everyday lessons.

The school, in a gentrified neighborhood in a city that has become less affordable for families and teachers alike, would not exist in its current form without the kind of education reform that has gained Denver both a national reputation and opposition from the union and its allies.

“We have worked really hard to build a positive and trusting culture,” said Munro, who has been principal for eight years. “Even that being said, trying times can make any situation difficult.”

Of the 32 teachers, nurses, counselors, and other educators at Centennial covered by the teachers contract, all but six took part in the strike on Monday, Munro said. One teacher returned to the classroom Tuesday, and a nurse came back Wednesday, she said.

Those are higher strike participation figures than in the district as a whole. Between 56 and 58 percent of teachers were out each day, Denver Public Schools has said.

Savinar was among those Centennial teachers who remained in the classroom. But it wasn’t because she disagreed with the union’s opposition to many aspects of ProComp, the once-promising pay-for-performance system that was the subject of negotiations.

Savinar recently took maternity leave, much of it unpaid. She and her husband crunched the numbers —  taking into account that teachers strikes typically last a week — and concluded that foregoing a paycheck, as striking teachers must do, was not something they could afford.

The irony is not lost on Savinar: She couldn’t afford to strike to improve her salary prospects.

“There was a lot of thought behind it, and it was definitely a financial decision,” she said, pointing out that her Centennial colleagues who remained in classrooms all have children 1 or younger. “It was a very challenging decision for every single person, I’m sure.”

A ninth-year teacher, Savinar left a job in neighboring Jeffco Public Schools to join Centennial four years ago. She said she was won over by the people and by expeditionary learning.

The school has a vegetable garden, an outdoor classroom with log benches, and a devoted corps of parent volunteers. For a recent lesson on biodiversity, Savinar took her students to Denver Botanic Gardens to visit a rainforest exhibit. They learned about different habitats and species of plants. Students who are now working on writing first-person narratives written from an animal’s perspective, like a jaguar or an exotic bird that makes its home in the lush canopy.

That a district-run public school would offer a model like expeditionary learning is unusual, and it’s part of Denver Public Schools’ philosophy of offering families a variety of school choices.

Centennial is also an innovation school, which means it doesn’t need to follow all aspects of state law or the teachers union contract. That allows for a much longer school day, for one. The opening bell rings at 8 a.m. and dismissal is at 3:45 p.m., with an 80-minute enrichment period.

Savinar is a “teacher-leader,” spending part of her time teaching and part of it coaching other teachers — another initiative that other U.S. school districts look to Denver to emulate.

Savinar said her support for the union stance during ProComp bargaining was rooted mostly in supporting an increase in all teachers’ base pay and in cost-of-living increases. She said she loves the flexibility that innovation status affords teachers and students both.

“It’s all relative, I guess,” she said. “Completely depends on what teachers are wanting in their school community.”

During the strike, Munro kept a detailed spreadsheet of classroom assignments, using a combination of regular teachers, substitutes, central office staff temporarily reassigned to schools, and her own preschool teachers who were available because DPS shut its preschools.

All but two classrooms were covered by certified teaching staff during the strike, she said.

Because of the timing of the tentative agreement, Thursday was more chaotic than when teachers were on strike, she said. Although all the striking teachers returned, the school retained a few substitutes to honor their commitments. Central office staff helped cover classrooms until late-arriving teachers got to work, then went back to their regular jobs.

“People had been gone three days and were just trying to put the puzzle pieces back together,” Savinar said. “People were scrambling a little bit because teachers are always prepared for their students, and they were feeling unprepared, coming into I am not sure what.”

Centennial will move on from the disruption of the strike at a time it faces its owns challenges. What was once a predominantly Latino student population has grown whiter and wealthier, driven by neighborhood changes and the appeal of expeditionary learning.

Having fewer students whose families live in poverty cost Centennial its Title I status, and the extra funding that goes with it. Munro said school officials knew it was coming and planned accordingly, accounting for the lost revenue over a two-year period and lessening the blow.

The older grades at Centennial are more diverse than kindergarten and the earlier grades, so as a fifth-grade teacher Savinar has a more diverse class than most.  

Next up, her students will begin a module on inequality. She and a returning colleague struck upon an idea Thursday: including a discussion about the issues underlying the strike. It’s in keeping with expeditionary learning’s aspiration to connect learning to real-world events.

So in the near future, Nic Savinar’s fifth-grade students at Centennial Elementary could talk about the issues that kept their teacher in school while her colleagues picketed outside.