Many Oklahoma schools remained shuttered for a second day on Tuesday as teachers continued to rally for higher wages and an increase in school funding.

The two-day rally comes on the heels of a pay raise for teachers signed by Republican Gov. Mary Fallin last week, which increased teachers' pay by 15 to 18 percent.

But protesting educators and school employees said they need more from the state after years of struggling with outdated textbooks, broken desks and shorter school weeks due to a lack of desperately needed funding. Some teachers at Monday's rally said they were forced to raise funds for basic school supplies or pay for them themselves.

“If I didn’t have a second job, I’d be on food stamps,” said Rae Lovelace, a single mom and a third-grade teacher at Leedey Public Schools in northwest Oklahoma who works 30 to 40 hours a week at a second job teaching online courses for a charter school.

At least 27 school districts in Oklahoma — including Oklahoma City, Tulsa and Edmond, the three largest in the state — remained closed on Tuesday, according to NBC News affiliate KFOR.

In a statement on Monday evening, Fallin noted that she had signed legislation that allowed for $50 million "for the state aid funding formula and textbooks," which amounted to a nearly 20 percent increase in such appropriations.

"Just like Oklahoma families, we are only able to do what our budget allows. Significant revenue-raising measures were approved to make this pay raise and additional school funding possible," Fallin said. "We must be responsible not to neglect other areas of need in the state such as corrections and health and human services as we continue to consider additional education funding measures."

Democratic lawmaker Collin Walke said teachers should keep up the pressure. Two separate bills pending in the Legislature to expand tribal gambling and eliminate the income tax deduction for capital gains could generate more than $100 million in additional funding each year.

“I think the Republican strategy is to wait the teachers out,” Walke said.

But many teachers on Monday said they planned to protest as long as it takes to get the increases they're after. For them, the $50 million increase in general education funding signed last week isn't enough.

Jason Simeroth, the superintendent of schools in Yukon, Oklahoma, told MSNBC that in his district alone it would cost $1 million to replace all of the outdated math textbooks.

"I think one of the things when people see this, they say, 'The teachers got a raise.' They did. It's the first one in long time, but they’re not just here for that," Simeroth said. "They’re here for resources, here for desks. ... We haven’t had an operational increase since I’ve been doing this, and I’ve been doing this 27, 28 years."